Abstract: In this paper, we use one a week data(the sampling interval of satellite clock is 30 s) of six IGS tracking stations to test the positioning accuracy and convergence time under PPP fixed ambiguity pattern-PPP_AR mode and conventional float solution mode. The results show that under PPP_AR solving mode, and for selfconsistency between the data, positioning accuracy of RMS can be smaller than 1 cm in both E-W and N-S directions, and in the U-D direction smaller than 3.5 cm, The results are obviously better than that of the conventional floatingpoint solution mode. The ambiguity fixed rate under PPP_AR mode is larger than 93％, the convergence time of PPP_AR mode focused on 20～25 min, while of the float solution mode on 25～35 min.