Abstract: We develop a new strategy for evaluating the GPS stochastic model in long baseline scenario.Firstly,we employ high frequency pass filtering of multiple differences in time domain to efficiently eliminate the systematic biases.Then,the mathematic models are proposed to assess the different aspects of GPS stochastic characteristics.Finally,the real GPS data is used to demonstrate the performance of the developed models.The findings can benefit the quality evaluation and integrity of CORS measurements and the quality control of positioning results in rover end.