Landslide of colluviums often occurs during or after heavy rainfall because the huge quantity of precipitation induces the upsurge of groundwater table as well as the reduction of effec-tive stress of soil stratum and the factor of safety from slope sta-bility analysis. Moreover,the longer duration of heavy rainfall maintain the higher groundwater table,the shear strength parame-ters may be decline due to the soil being soaked for longer period of time. The campus of Huafan University is mostly covered by colluviums that located on Mt. Da-Lum,Shih-Tin Hsiang,Taipei County,Taiwan,China. Slope stability is one of the major con-cerned issues,for this reason,a slope monitoring test site has been established around the campus. According to the data collected,the magnitude of slope movement influenced by rainfall can be observed. In this study,the colluviums samples are collected from the campus of Huafan University and direct shear tests are per-formed to obtain the shear strength parameters of the remolded soil samples that soaked in the water for various periods of time,i.e. 0,1,2,3,5 and 7 days respectively. From these tests,the change of the shear strength and slope stability of colluviums with respect to the soaking time of soil has been further understood. Landslide of colluviums often occurs during or after heavy rainfall as the huge quantity of precipitation induces the upsurge of groundwater table as well as the reduction of effec-tive stress of soil stratum and the factor of safety from slope sta-bility analysis. longer duration of heavy rainfall maintain the higher groundwater table, the shear strength parame-ters may be decline due to the soil being soaked for longer period of. The campus of Huafan University is mostly covered by colluviums that located on Mt. Da-Lum , Shih-Tin Hsiang, Taipei County, Taiwan, China. Slope stability is one of the major con-cerned issues, for this reason, a slope monitoring test site has been established around the campus. According to the data collected, the magnitude of slope movement influenced by rainfall can be observed. In this study, the colluviums samples were collected from the campus of Huafan University and direct shear tests are per-formed to obtain the shear strength parameter s of the remolded soil samples that soaked in the water for various periods of time, ie 0, 1, 2, 3, 5 and 7 days respectively. From these tests, the change of the shear strength and slope stability of colluviums with respect to the soaking time of soil has been further understood.