I. Introduction
From 1990s, the stabilization control of stochastic nonlinear systems has been extensively studied. This problem was initially studied by Florchinger [1]–[3]. In their work, the control Lyapunov function and Sontag stabilization formular was generalized to stochastic case. An essential improvement was that Pan and Basar ([5]) etc, provided the backstepping controller design method for strict feedback systems by using the quadratic Lyapunov functions and risk sensitive cost criteria([6]–[9]). Another essential improvement contributes to Krstić and Deng. By introducing quartic Lyapunov function, the asymptotical stabilization controller was designed by Deng, Krstić and Williams in [10]–[12] and [13]. From that, the stability and stabilization for many class of stochastic nonlinear systems ([14], [15], etc.) are studied.