Based on the mass and momentum conservations of the continuum，this paper presents a novel coupled material point method based on the v-w formulation，which fully considers the large deformation mechanics of saturate and unsaturated structures under the interactions between the solids and the fluids. For simplicity，the gas phase is neglected in the formulation，while an additional item，i.e. degree of saturation，is incorporated in the gov? erning equations to simply study the saturated/unsaturated soils. The detailed derivation process of the governing equations，discretization process in the matrix forms and the computational cycles of CMPM is introduced. Via two benchmark examples，i.e. one-dimensional Terzaghi consolidation solution，and the Liakopoulos test，the validity of the CMPM is proven. In the end，a slope failure analysis due to the rainfall infiltration is presented，where both deep progressive and superficial slope failures are shown，further demonstrating that CMPM is a promising tool in simulat? ing hydro-mechanical problems.