Recently Business Process Management System (BPMS) has become one of the hottest research topics related to enterprise information systems. Based on some requirements in the emerging BPMS, this paper proposes an original architecture on a hybrid Business Process Design and Verification System (BPDVS). This architecture attempts to build a system that integrates the informal and formal approaches in the BPM related fields. In this way it can obtain practicability and robustness, which are presently strengths separately from the informal and formal approaches. The industrial standard XPDL is used as the informal process description language while a logic language Situation Calculus is employed as the underlying formalism to precisely specify a process. The hybrid BPDVS will integrate these two different process models and attempts to provide a more integrative and dynamic design environment for business processes.