Abstract: To overcome the defects of the depth estimation of buried structures by the empirical method, a new method to estimate the depth based on the reflected waveform characteristics of buried targets was put forward by extracting few points from the reflected waveform. Accuracy analysis was performed in consideration of waveform distortion. The resuhs show that on ideal undistorted ground penetrating radar (GPR) data, the proposed method is accurate in estimating the depth and the horizontal position of buried targets, as well as the electromagnetic wave speed. An average error of 55.202% occurs in depth estimation based on distorted waveform data even though the estimation result of wave speed is accurate as before. So the method is corrected to confirm the depth of buried targets using the estimated wave speed and the two-way travel time of the reflected wave from the structures when facing distorted GPR data, and the accuracy of estimation satisfies the requirements of the GPR method. This method is more satisfactory and robust compared with the empirical method.