A variable structure control algorithm is presented for a class of linear stochastic system with uncertain condition.After the algorithm fully considering the interaction among system states

a sliding mode hyperplane is designed with the robust control theory.First

the robust feedback control is designed for the uncertain sub-system without control input

and then the final control is obtained based on the sliding mode control theory.On the condition that the stochastic system satisfies Ito^ differential

it is proved with Lyapunov method that the sliding mode hyperplane is reachable and the uncertain stochastic system is asymptotically stable by variable structure control.The numerical results show the effectiveness of the proposed control algorithm.