Abstract: The soil in slip zone is the vital section of the landslide, the strength characteristic has important effect on the stability of slope. Because Huangtupo landslide in Three Gorges Reservoir area has been affected by variation of reservoir water level and rainfall, water content of soil in slip zone is always in the process of changing, this produces much influence on the strength parameter of soil in slip zone. According to this thought, some soil samples in slip zone of Huangtupo's second landslide near river were taken, undrained quick direct shear test for the soil in slip zone with different water content was conducted. The parameters of internal friction angle(φ) and cohesion(C) influenced by water content of soil in slip zone were acquired through test.