And then, some synchronization techniques, which are semaphore, mutex, event and critical section used in VC++ and synchronized key word used in JAVA, are introduced. 介绍了在VC++中用信号量、互斥体、事件和临界区四种对象实现和在JAVA中用Synchronized关键字实现的同步技术。最后,对改进多线程应用的性能和安全提出了一些策略。