The single-factor perturbation analysis method was used for the sensibility analysis of soil hydraulic parameters, including the residual water content θ_r, the saturated water content θ_s, the saturated hydraulic conductivity K_s, the empirical parameters α and n. With the help of HYDRUS-1D model, the process of water infiltration in the soil was simulated for the two-year-once storm in Nanjing and the sensitivity of soil hydraulic parameter was evaluated for the varying-head infiltration, which can quantitatively describe the effects of soil hydraulic parameters on two output variables of HYDRUS-1D(soil water potential and cumulative infiltration), simplify the model calibration and improve the accuracy of model simulation. The results show that under the condition of varying-head infiltration, the parameter’s influence degree on both soil water potential and cumulative infiltration are in this order: n>K_s>θ_s>α>θ_r. Empirical parameters α and n have a great influence on the soil water potential with a depth of 0~10 cm beneath the surface, and the influence are similar when changing parameters K_s, θ_r or θ_s and α on the soil water potential. In the case of ±25% disturbance, the influence degree of θ_s, K_s and n on the cumulative infiltration are more than 10%. Therefore, the accuracy of K_s, θ_s, α and n should be ensured during the simulation of varying-head infiltration.