Abstract: Several horizontal push-shear in-situ tests on SRM in an immersion state under water were carried at Long pan slope in Tiger-Leaping Gorge,and some significant conclusions were drawn.In order to gain reliable values of the strength parameters,an average sliding surface was put forward in calculation through in-situ horizontal push-shear test.Comparing the strength parameters in immersion state under water with those in natural state,a variation for rule of the strength parameters of SRM was achieved.In the end,the referential values of the strength parameters of the water immersed SRM in test area were given.