摘要: Aim　Tostudy the unstability of Chaplygin system's equilibrium state manifold under the randomperturbation. Methods　Firstly, the stochastic differential equations ofChaplygin system was established; then, the first and second linearization momentequations corresponding to the system were given, at last, the moment unstability of thestochastic system according to the theory of Liapunov was judged. Results andConclusion　The criterion for juaging the unstability of stochastic Chaplyginsystem was obtained and one example was given to illustrate the application of thecriterion.