Abstract: Traditional business process integration procedure includes five main steps which are integration modeling, integration simulation, integration execut ion, integration monitoring and integration optimization. These steps form a clo sed loop which can achieve optimal outcome. Though the procedure has been applie d by some corporations, it still has some limitation in practice. This paper com bines the procedure mentioned above with hierarchical Petri net to introduce a n ew procedure of business process integration which is used to solve the problem of long lifecycle and great expense of the traditional integration procedure. Me anwhile, the paper also focuses on the core step of this integration procedure- business process integration modeling in detail, which will provide theoretical basis for the practice.