With the widespread application of mobile agents, mobile agent system’s security is a prominent problem to be solved, and mobile agent’s security question is critical. This paper proposes a mobile agent security architecture based on cryptography and computer network security. At the same time, the practical methods and suggested ways can be used in other new security measures. The purpose is for these measures do not only ensure the security of mobile agent communication and mobile agent execution environment, but at the same time ensure that this securidy system can be applied more widely to more mobile agents.