Abstract: According to the problem of exception handling for WS-BPEL in service oriented software, this paper presented an approach for BPEL's exception handling based on color petri net(CPN). Through formalizing description of exception handling mechanism of BPL,the approach builds exception handling CPN model,instructs the development of BPEL's exception handling logic, and based on this modeling idea, gives a converting tool for the BPEL's exception handling CPN model,which converts the BPEL's exception handling CPN model into BPEL codes with exception handling function, and through danamically adding exception handling elements of 13PEI，the tool can produces new BPEL process with exception handling. Finally we represented a case study to illustrate the using process and prove the affectivity of our method.

Key words: Color Petri net,BPEL(Business Process Execution Language)，Exception handling