People have to do a large of simulation and analyses when they design the structure and protocol of the computer and communication network system, and the network project and design, this paper introduces advanced network simulation software-OPNET. 在计算机和通信网络系统的结构与协议设计及网络规划设计时,常常要进行大量的仿真分析,本文介绍的就是一种先进的网络仿真软件OPNET。