Abstract: A numerical simulation was performed to analyze the influence of outliers on GPS kinematic relative positioning.The influence function of errors and the method of robust estimation are given.In order to deal with the outliers in GPS airborne kinematic relative positioning,a combining method of outlier detection and robust estimation is proposed.It includes two steps: firstly,the gross errors are detected and deleted based on the median method in the data preprocessing;then the residual outliers is controlled by the robust estimation in the parameter adjustment.To verify the validation of this method,several experiments are performed.The results show that the influence of the outliers can be effectively controlled and the computing speed is improved,when the combining method are adopted.The kinematic positioning results are compared with those of TGO software and GAMIT software,which shows that the positioning precision of proposed method is about cm-level.