Concurrent programs written in a machine level language are being used in many areas but verification of such programs brings new challenges to the programming language community. Most of the studies in the literature on verifying the safety properties of concurrent programs are for high-level languages,specifications, or calculi. Therefore, more studies are needed on concurrency verification for machine level language programs. This paper describes a framework of a Petri net based safety policy for the verification of concurrent assembly programs, to exploit the capability of Petri nets in concurrency modeling. The concurrency safety properties can be considered separately using the net structure and by mixing Hoare logic and computational tree logic. Therefore, more useful higher-level safety properties can be specified and verified.