In this paper, a class of semi-implicit two-stage STOCHASTIC Runge-Kuttamethods (SRKs) of strong global order one, with minimum principal er-ror constants are given. These methods are applied to solve It^o stochas-tic di ERENTIAL EQUATIONS (SDEs) with a Wiener process. The e ciency ofthis method with respect to explicit two-stage It^o Runge-Kutta methods(IRKs), It^o method, Milstien method, semi-implicit and implicit two-stageStratonovich Runge-Kutta methods are demonstrated by presenting somenumerical results.