Abstract: A time delay discrete time model of multi-input and multi-output(MIMO)networked control system is derived which includes communication time delays of control networks.A new stability analysis method of networked control system is provided,and the conditions of network time delay which can make system stable are derived.If the network time delay of networked control system satisfies these conditions,the poles of networked control system are in a circular area on the complex plane.Networked control system is stable on condition that this circular area is in a(unit circle.)A simulation experiment illustrates the effectiveness of the presented theory.