This paper deals with the design of stable sliding mode control (SMC) for the underactuated slosh-container system using feedforward normal form. A nonlinear coordinate transformation is used to convert the system into so called feedforward normal like form to decouple the control input appearing in one of the degree of freedom (DOF). This results in the design simplicity for the sliding mode control as well as the equivalent control and reduced order system derivation and its stability analysis. The range of surface parameters to provide the stable sliding motion for the system using proposed scheme, is also large compared to our earlier results. Simulation results are also presented to illustrate the proposed method. © 2014 IEEE.