The rotating components of aerial target can have modulation effect on radar echo. Taking the rate deviation coefficient as a modulation characteristic，the differences between fixed-wing aircrafts and helicopter aircrafts are analyzed with simulation data. A nearest neighbor classifier method is proposed. The targets are classified by using the measured data，and a higher recognition rate is obtained. In contrast with the support vector machine algorithm，the proposed method bears low complexity，less computation and high recognition rate. It can be used to classify two types of targets in engineering project.