Abstract:Three kinds of mapping functions such as Neill mapping function (NMF), Vienna mapping function1 (VMF1) and global mapping function (GMF) are introduced in this paper. The two indexes: baseline repeatability and standard deviation of the mean value for GPS baseline quality assessment, are discussed. According to the observation data of the IGS station in China, the data processing results based on GAMIT are used to research and analyze the influence of these three kinds of mapping functions on GPS baseline repeatability and standard deviation of the mean value. The results show that the calculation accuracy of dynamic mapping functions is higher than empirical mapping functionsin GPS baseline processing.In the solution of baseline repeatability, the VMF1 model is better than GMF model, but the GMF model is better in calculation of standard deviation of the mean value.