Using simulation environments to support mobile distributed application development has many benefits. Since mobile devices can be modeled as autonomous intelligent agents, the multi agent based simulation (MABS) approach is useful for such applications. In this paper, we propose a MABS platform on the computational Grid for mobile distributed computing. A prototype of the proposed platform is implemented and its performance characteristics are studied. The findings of the experiment show that a Grid based MABS platform can provide a scalable simulation environment for mobile distributed applications.