BPEL is a language that could express complex con- current behaviors. This paper presents a novel method of BPEL test case generation, which is based on concurrent path analysis. This method first uses an Extended Control Flow Graph (XCFG) to represent a BPEL program, and generates all the sequential test paths from XCFG. These sequential test paths are then combined to form concurrent test paths. Finally a constraint solver BoNuS is used to solve the constraints of these test paths and generate feasible test cases. Some techniques are proposed to reduce the number of combined concurrent test paths. Some test criteria de- rived from traditional sequential program testing are also presented to reduce the number of test cases. This method is modularized so that many test techniques such as various test criteria and complex constraint solvers can be applied. This method is tested sound and efficient in experiments. It is also applicable to the testing of other business process languages with possible extension and adaption.