As a number of software evolution process models increased, as modeled by EPMM (software evolution process meta model), verifying the correctness of these models becomes the important. This paper extends EPMM with ACP (algebra of communicating processes) and proposes EPMM-A (software evolution meta modelalgebra). In order to discuss behavior verification in the unified framework of EPMM-A, a process term is used to define an algebraic semantics of a software evolution process model. Based on equational reasoning of EPMM-A, behavior verification of a software evolution process model emphasizes algebraic reasoning as opposed to modelbased reasoning. This method combines the advantages of both Petri nets and ACP, which can effectively support software evolution process formal verification.