Verification is one of the most important steps in modeling and simulation. However, behavior modeling is extremely complex, especially in battlefield simulations. Till now, there are few efficient methods for behavior verification of computer generated forces. In this paper, a novel approach is proposed based on the theory of Abstract State Machines (ASM), which is usually used in the field of model-based software testing. In our work, Behaviors of CGF are described in ASML, which is a kind of specification language of ASM. With this approach, the verification of the states of CGF behaviors can be possibly achieved at the design stage, and we can improve our behavior design then. Keywords-Abstract state machine, AsmL, Computer generated forces, Behavior