The development of network has greatly promoted the information communication and the data sharing. Many people are trying their best to develop new programming technologies to utilize the network more efficiently. The idea of performing client-server computing by transmission of executable programs between clients and servers has become highly popular among researchers and developers who are engaged in intelligent network services. Computing based on mobile agents is an important aspect of this idea. This paper focuses on the research of the migration process of agents.A model based on modules is devised for constructing agents.Aconcurrent schedule method is prented,by which the agent migration can be easily implemented.Most of the unnecessary tran smission of codes and data can be avoided by module reuse.Consequently,the executing period of mobile agents is reduced and their efficiency is improved.