Abstract: Due to the less prior constraint information, the ambiguity resolution and positioning performance are not very good in the GPS single-epoch kinematic positioning parameter estimation. Thus, a new method of GPS single-epoch kinematic positioning based on Doppler velocimetry is proposed in this paper. The coordinate initialization using the velocity information is firstly discussed, the current epoch's coordinate of the moving vehicle is predicted with the priori coordinate and velocity information. Compared with the conventional method of single point positioning (SPP) coordinate initialization, it is expected to obtain higher precision, but poorer robustness as well. Thus, the corresponding strategy for single-epoch ambiguity resolution is further introduced so as to improve the positioning performance of the method in this paper. Contrasting with the conventional algorithm of GPS single-epoch kinematic positioning, the experimental results show that, the method proposed can improve the precision of the float ambiguity, the final ambiguity fixed rate and the average positioning accuracy, especially in the case that, the number of GPS satellites is not sufficient or the geometric structure of the satellites is not very good.