In the research and development of concurrent systems, there is an urgent need for a formal method which can effectively specify the dynamic process topologies and dynamic inter-process communication behaviors of concurrent systems, and for a system testing method which is based on the formal specification method and can detect the dynamic transformations of system states. This paper gives a system testing method of concurrent systems which is based on graph grammar. The testing method can automatically trace and record the running states and communication histories according to the testing requirements given by system developers. The developers can get the current system state of a running concurrent system in realtime, or replay the transformation process of system states at any timeneeded. The implementation algorithms of this method are also described.