Hi all.. I am beginner in Java. My problem is: I am calling a Java class's method from c++. For this i am using JNI. Everythings works correct, but i have some memory LEAKS in the process of c++ program... So.. i did simple example.. 1) I create a java machine (jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);) 2) then i take a pointer on java class (jclass cls = env-FindClass("test_jni")); 3) after that i create a java class object object, by calling the constructor (testJavaObject = env-NewObject(cls, testConstruct);) AT THIS very moment in the process of c++ program is allocated 10 MB of memory 4) Next i delete the class , the object, and the Java Machine .. AT THIS very moment the 10 MB of memory are not free ................. So below i have a few lines of code c++ program void main() { { //Env JNIEnv *env; // java virtual machine JavaVM *jvm; JavaVMOption* options = new JavaVMOption[1]; //class paths options[0].optionString = "-Djava.class.path=C:/Sun/SDK/jdk/lib;D:/jms_test/java_jni_leak;"; // other options JavaVMInitArgs vm_args; vm_args.version = JNI_VERSION_1_6; vm_args.options = options; vm_args.nOptions = 1; vm_args.ignoreUnrecognized = false; // alloc part of memory (for test) before CreateJavaVM char* testMem0 = new char[1000]; for(int i = 0; i < 1000; ++i) testMem0[i] = 'a'; // create java VM jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args); // alloc part of memory (for test) after CreateJavaVM char* testMem1 = new char[1000]; for(int i = 0; i < 1000; ++i) testMem1[i] = 'b'; //Creating java virtual machine jclass cls = env->FindClass("test_jni"); // Id of a class constructor jmethodID testConstruct = env->GetMethodID(cls, "<init>", "()V"); // The Java Object // Calling the constructor, is allocated 10 MB of memory in c++ process jobject testJavaObject = env->NewObject(cls, testConstruct); // function DeleteLocalRef, // In this very moment memory not free env->DeleteLocalRef(testJavaObject); env->DeleteLocalRef(cls); // 1!!!!!!!!!!!!! res = jvm->DestroyJavaVM(); delete[] testMem0; delete[] testMem1; // In this very moment memory not free. TO /// } int gg = 0; } java class (it just allocs some memory) import java.util.*; public class test_jni { ArrayList<String> testStringList; test_jni() { System.out.println("start constructor"); testStringList = new ArrayList<String>(); for(int i = 0; i < 1000000; ++i) { // ??????? ?????? testStringList.add("TEEEEEEEEEEEEEEEEST"); } } } process memory view, after crating javaVM and java object: testMem0 and testMem1 - test memory, that's allocated by c++. ************** testMem0 ************** JNI_CreateJavaVM ************** testMem1 ************** // create java object jobject testJavaObject = env->NewObject(cls, testConstruct); ************** process memory view, after destroy javaVM and delete ref on java object: testMem0 and testMem1 are deleted to; ************** JNI_CreateJavaVM ************** // create java object jobject testJavaObject = env->NewObject(cls, testConstruct); ************** So testMem0 and testMem1 is deleted, But JavaVM and Java object not.... Sow what i do wrong... and how i can free memory in the c++ process program.