Based on the analysis of the current mobile agent systems and MASIF (mobile agent system interoperability facility), a template architecture for mobile agent system of high security called Jamogents including the architectures of both mobile agent itself and its supporting environment (MASE) are proposed in this paper. The working flow of Jamogents is also described. To make Jamogents secure, an algorithm called RIM, which implements both encryption and digital signature, is also discussed and implemented.