In high frequency region,the radar range profiles are chosen as feature vectors for target recognition.The profile is seriously affected by the bearing.In order to make the radar target recognition more sffective,the definitions of correlation length and correlation angle are given.In frequency domain,the most important feature of the shape of a profile is mainly contained in its spectral phase, but not in its spectral magnitude.So the spectral phase is important feature information for RTR(Radar Target Recognition) in high frequency region,and should be utilized effectively.