As a primary research matter,the Cosimulation technology is used to resolve the simulation of complexity system. This paper introduces a software which supports cosimulation——Plug sim, and the instance of cosimulation under the Plug sim. As a circumstance for cosimulation, not a simulation software, Plug sim must have a simulation tool, which can be supported by Plugsim to model and simulate. So this paper expatiates the instance of MATRIXx cosimulation based on the circumstance of Plug sim.