diff --git a/core/pom.xml b/core/pom.xml
index 32bfbee62..cce76380e 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -70,6 +70,11 @@
             <artifactId>arthas-common</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.taobao.arthas</groupId>
+            <artifactId>arthas-memorycompiler</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.ow2.asm</groupId>
             <artifactId>asm</artifactId>
diff --git a/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java b/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
index 712c97882..f9693c456 100644
--- a/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
+++ b/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
@@ -17,6 +17,7 @@ import com.taobao.arthas.core.command.klass100.ClassLoaderCommand;
 import com.taobao.arthas.core.command.klass100.DumpClassCommand;
 import com.taobao.arthas.core.command.klass100.GetStaticCommand;
 import com.taobao.arthas.core.command.klass100.JadCommand;
+import com.taobao.arthas.core.command.klass100.MemoryCompilerCommand;
 import com.taobao.arthas.core.command.klass100.OgnlCommand;
 import com.taobao.arthas.core.command.klass100.RedefineCommand;
 import com.taobao.arthas.core.command.klass100.SearchClassCommand;
@@ -69,6 +70,8 @@ public class BuiltinCommandPack implements CommandResolver {
         commands.add(Command.create(JvmCommand.class));
         // commands.add(Command.create(GroovyScriptCommand.class));
         commands.add(Command.create(OgnlCommand.class));
+        commands.add(Command.create(MemoryCompilerCommand.class));
+        commands.add(Command.create(RedefineCommand.class));
         commands.add(Command.create(DashboardCommand.class));
         commands.add(Command.create(DumpClassCommand.class));
         commands.add(Command.create(JulyCommand.class));
@@ -81,7 +84,6 @@ public class BuiltinCommandPack implements CommandResolver {
         commands.add(Command.create(SessionCommand.class));
         commands.add(Command.create(SystemPropertyCommand.class));
         commands.add(Command.create(SystemEnvCommand.class));
-        commands.add(Command.create(RedefineCommand.class));
         commands.add(Command.create(HistoryCommand.class));
     }
 }
diff --git a/core/src/main/java/com/taobao/arthas/core/command/klass100/ClassLoaderCommand.java b/core/src/main/java/com/taobao/arthas/core/command/klass100/ClassLoaderCommand.java
index f93189fc5..ca0db73ef 100644
--- a/core/src/main/java/com/taobao/arthas/core/command/klass100/ClassLoaderCommand.java
+++ b/core/src/main/java/com/taobao/arthas/core/command/klass100/ClassLoaderCommand.java
@@ -65,7 +65,7 @@ public class ClassLoaderCommand extends AnnotatedCommand {
     }
 
     @Option(shortName = "c", longName = "classloader")
-    @Description("Display ClassLoader urls")
+    @Description("The hash code of the special ClassLoader")
     public void setHashCode(String hashCode) {
         this.hashCode = hashCode;
     }
diff --git a/core/src/main/java/com/taobao/arthas/core/command/klass100/MemoryCompilerCommand.java b/core/src/main/java/com/taobao/arthas/core/command/klass100/MemoryCompilerCommand.java
new file mode 100644
index 000000000..01aad6a74
--- /dev/null
+++ b/core/src/main/java/com/taobao/arthas/core/command/klass100/MemoryCompilerCommand.java
@@ -0,0 +1,131 @@
+package com.taobao.arthas.core.command.klass100;
+
+import java.io.File;
+import java.lang.instrument.Instrumentation;
+import java.nio.charset.Charset;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import com.taobao.arthas.compiler.DynamicCompiler;
+import com.taobao.arthas.core.command.Constants;
+import com.taobao.arthas.core.shell.command.AnnotatedCommand;
+import com.taobao.arthas.core.shell.command.CommandProcess;
+import com.taobao.arthas.core.util.ClassLoaderUtils;
+import com.taobao.arthas.core.util.FileUtils;
+import com.taobao.arthas.core.util.LogUtil;
+import com.taobao.arthas.core.util.affect.RowAffect;
+import com.taobao.middleware.cli.annotations.Argument;
+import com.taobao.middleware.cli.annotations.Description;
+import com.taobao.middleware.cli.annotations.Name;
+import com.taobao.middleware.cli.annotations.Option;
+import com.taobao.middleware.cli.annotations.Summary;
+import com.taobao.middleware.logger.Logger;
+
+/**
+ *
+ * @author hengyunabc 2019-02-05
+ *
+ */
+@Name("mc")
+@Summary("Memory compiler, compiles java files into bytecode and class files in memory.")
+@Description(Constants.EXAMPLE + "  mc /tmp/Test.java\n" + "  mc -c 327a647b /tmp/Test.java\n"
+                + "  mc -d /tmp/output /tmp/ClassA.java /tmp/ClassB.java\n" + Constants.WIKI + Constants.WIKI_HOME
+                + "mc")
+public class MemoryCompilerCommand extends AnnotatedCommand {
+
+    private static final Logger logger = LogUtil.getArthasLogger();
+
+    private String directory;
+    private String hashCode;
+    private String encoding;
+
+    private List<String> sourcefiles;
+
+    @Argument(argName = "sourcefiles", index = 0)
+    @Description("source files")
+    public void setClassPattern(List<String> sourcefiles) {
+        this.sourcefiles = sourcefiles;
+    }
+
+    @Option(shortName = "c", longName = "classloader")
+    @Description("The hash code of the special ClassLoader")
+    public void setHashCode(String hashCode) {
+        this.hashCode = hashCode;
+    }
+
+    @Option(longName = "encoding")
+    @Description("Source file encoding")
+    public void setEncoding(String encoding) {
+        this.encoding = encoding;
+    }
+
+    @Option(shortName = "d", longName = "directory")
+    @Description("Sets the destination directory for class files")
+    public void setDirectory(String directory) {
+        this.directory = directory;
+    }
+
+    @Override
+    public void process(CommandProcess process) {
+        int exitCode = 0;
+        RowAffect affect = new RowAffect();
+
+        try {
+            Instrumentation inst = process.session().getInstrumentation();
+            ClassLoader classloader = null;
+            if (hashCode == null) {
+                classloader = ClassLoader.getSystemClassLoader();
+            } else {
+                classloader = ClassLoaderUtils.getClassLoader(inst, hashCode);
+                if (classloader == null) {
+                    process.write("Can not find classloader with hashCode: " + hashCode + ".\n");
+                    exitCode = -1;
+                    return;
+                }
+            }
+
+            DynamicCompiler dynamicCompiler = new DynamicCompiler(classloader);
+
+            Charset charset = Charset.defaultCharset();
+            if (encoding != null) {
+                charset = Charset.forName(encoding);
+            }
+
+            for (String sourceFile : sourcefiles) {
+                String sourceCode = FileUtils.readFileToString(new File(sourceFile), charset);
+                String name = new File(sourceFile).getName();
+                if (name.endsWith(".java")) {
+                    name = name.substring(0, name.length() - ".java".length());
+                }
+                dynamicCompiler.addSource(name, sourceCode);
+            }
+
+            Map<String, byte[]> byteCodes = dynamicCompiler.buildByteCodes();
+
+            File outputDir = null;
+            if (this.directory != null) {
+                outputDir = new File(this.directory);
+            } else {
+                outputDir = new File("").getAbsoluteFile();
+            }
+
+            process.write("Memory compiler output:\n");
+            for (Entry<String, byte[]> entry : byteCodes.entrySet()) {
+                File byteCodeFile = new File(outputDir, entry.getKey().replace('.', '/') + ".class");
+                FileUtils.writeByteArrayToFile(byteCodeFile, entry.getValue());
+                process.write(byteCodeFile.getAbsolutePath() + '\n');
+                affect.rCnt(1);
+            }
+
+        } catch (Throwable e) {
+            logger.warn("Memory compiler error", e);
+            process.write("Memory compiler error, exception message: " + e.getMessage()
+                            + ", please check $HOME/logs/arthas/arthas.log for more details. \n");
+            exitCode = -1;
+        } finally {
+            process.write(affect + "\n");
+            process.end(exitCode);
+        }
+    }
+}
diff --git a/core/src/main/java/com/taobao/arthas/core/util/ClassLoaderUtils.java b/core/src/main/java/com/taobao/arthas/core/util/ClassLoaderUtils.java
new file mode 100644
index 000000000..7fd27ac37
--- /dev/null
+++ b/core/src/main/java/com/taobao/arthas/core/util/ClassLoaderUtils.java
@@ -0,0 +1,41 @@
+package com.taobao.arthas.core.util;
+
+import java.lang.instrument.Instrumentation;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ *
+ * @author hengyunabc 2019-02-05
+ *
+ */
+public class ClassLoaderUtils {
+
+    public static Set<ClassLoader> getAllClassLoader(Instrumentation inst) {
+        Set<ClassLoader> classLoaderSet = new HashSet<ClassLoader>();
+
+        for (Class<?> clazz : inst.getAllLoadedClasses()) {
+            ClassLoader classLoader = clazz.getClassLoader();
+            if (classLoader != null) {
+                classLoaderSet.add(classLoader);
+            }
+        }
+        return classLoaderSet;
+    }
+
+    public static ClassLoader getClassLoader(Instrumentation inst, String hashCode) {
+        if (hashCode == null || hashCode.isEmpty()) {
+            return null;
+        }
+
+        for (Class<?> clazz : inst.getAllLoadedClasses()) {
+            ClassLoader classLoader = clazz.getClassLoader();
+            if (classLoader != null) {
+                if (Integer.toHexString(classLoader.hashCode()).equals(hashCode)) {
+                    return classLoader;
+                }
+            }
+        }
+        return null;
+    }
+}