Abstract: The slaking stability of an excavated high slope of argillaceous soft rock is systematically studied. Based on the laboratory test results of undisturbed sample, the special mechanical characteristics are analyzed. The Bishop’s circular arc analysis is used to calculate the overall stability of slope in the natural state, residual shear strength state, as well as slaking state. According to the coefficients of Duncan model gained by laboratory tests, the nonlinear stressstrain characteristics of the excavated high slope under different stress state is studied by finite element method.Moreover, strengthened slope is calculated and analyzed using homologous model and coefficients. The results reveal that it is identical with the slope in the real state. The conclusion can be drawn that the strength attenuation due to rainfall infiltration and decompression relaxation must be taken into account in the design and analysis of argillaceous soft rock slope.