The characteristics of three GPS kinematical data processing models, Least Square, Kalman filtering, are discussed and their advantages and disadvantages are compared. With observational data and pertinent data processing software, the applicable condition, context and effect of the three models are experimented. Results show that when the mobile platform is in uniform motion, the accuracy of the three models are almost equal; when the mobile platform is in stochastic acceleration, the accuracy of new filtering model is superior to that of LS, and that of Kalman filtering is the worst.