Abstract: In view of the difference of period and noise characteristics in different regions, this paper takes the coordinate time series of 27 CORS in Shandong Province from 2015 to 2018 as the research object, and analyzed the period and noise of coordinate components of each station on the basis of data preprocessing. The results show that, there is no strict whole periodic signal in coordinate time series, and the periodic motion in U direction is relatively regular. The spectrum index of coordinate component shows that the noise model of most stations is white noise (WN) + flicker noise (FN). Using the maximum likelihood estimation criterion, the best noise model of coordinate time series in Shandong CORS station is WN + FN, and the best noise model in E and U direction is WN + FN. The best noise model is WN + FN + random walk noise (RWN).