Abstract: Estimating procession period based on ballistic missile targets Radar Cross Section (RCS) sequences is an important means of feature extraction and target identification. The RCS sequences of ballistic missile target are unstable random process when the target is in procession, and the conventional Fourier transform and correlation type method needs long observation time and high data rate to estimate the procession period, which are unacceptable to the limited radar resource. A novel method of estimating procession period based on RCS sequences is presented. The proposed method first fits the RCS sequences with trigonometric function of a certain frequency, then get a procession frequency that minimize the fitting errors of different frequencies trigonometric function. The proposed method estimate more accurately and needs fewer time resources than conventional ones, as is validated by the simulation results of RCS data.