This paper presents an analysis-method of concurrent processes with value-passing which may cause infinite-state systems. The method consists of two steps: sequentialisation and state-reduction. In the sequentialisation, the symbolic transition graph of a given concurrent process is derived by symbolic operational semantics. In the state-reduction, the number of states in the symbolic transition graph is reduced by removing needless internal transitions. Furthermore, this paper introduces an analysis-tool called CONPASU, which implements the analysis-method, and demonstrates how CONPASU can be used for automatically analyzing concurrent processes. For example, it can extract abstract behaviors, which are useful for understanding complex behaviors, by focusing on some interesting events.