Abstract: We present a real-time rendering method for soft shadows in dynamic scenes by approximating the model surface using circle splats.The occlusion of each of the splats can be approximated using an elliptical occlusion field which is sampled in the pre-computation process.In each sample point,an occlusion cubemap of single ellipse represented by spherical harmonic coefficients is got and we transferred them to logarithm using spherical harmonic logarithm algorithm.During the rendering,we first got the log SH coefficients of each circle splat according to the its normal,radius and the distance between the splat and the receiving point,which is precomputed.We accumulate the total occlusion coefficients in log space and compute the final SH coefficients using spherical harmonic exponentiation algorithm.The algorithm combines the circle splats approximating method and spherical harmonic exponentiation algorithm.It is so flexible that it can easily render soft shadow generated by both soft objects and dynamic solid objects.