In order to facilitate business collaboration and interoperation in virtual enterprises, it is crucial to discover appropriate business processes modeled in different languages and stored in different repositories. For this purpose, it is more efficient to register existent process models into a common process model registry, rather than defining numerous mappings from one modeling language to another. Considering the wide acceptance of BPEL, this paper proposed a common metamodel for process model registration (PMR), and defines the mappings from BPEL to PMR with corresponding mapping rules and algorithms. In this way, BPEL process models can be registered in the process model registry based on PMR automatically, and then the essential data from their registration information can facilitate process discovery across heterogeneous process repositories.