It was presented for the results of 3D finite difference analysis on the behavior of single pile in clay. Firstly, it was discussed to the effect of model’s mesh fineness and soil parameters on pile response. And it was founded that the mesh size less than 0.2d (diameter of pile) was reasonable. In additions, when the soil was soft or the E(soil elastic modulus) was small, the effect E of on lateral capacity of pile was larger than the soil was stiff clay with soil elastic modulus increasing. Lastly, the results of the numerical simulation carried out in this study were compared with a published field lateral loading tests, a good correlation between the field test and the numerical simulation was obtained based on reasonable mesh size and material parameters.