Abstract: As for landslides of cutting slopes in expansive soils owing to increasing water,the water content was taken into consideration to solve the problems.At first,two kinds of soil experiments were made,that is,expansive deformation experiment and shear strength experiment,and the variations of parameters of expansive soil property with the water content were generated.Then considering the proper geologic factors,a numerical model of cutting slopes was established by means of finite difference method,and the slope stability under different water-increased conditions was analyzed while all kinds of soil property parameters and water content varied synchronously.Finally,the safety factors of cutting slopes in expansive soil were gained by strength reduction method.According to the above analysis,it was shown that the stability of the slope was controlled by geology and water content.