In this paper, based on the China′s national time reference system of UTC (NTSC), the application study of BeiDou antenna phase center (APC) correction in precise point positioning (PPP) and high precision time comparison is carried out. Based on the data collected through BeiDou receiver, and the BeiDou precision products of clock, orbit and APC correction file downloaded from International GNSS Service (IGS) analysis center, the data processing of the BeiDou PPP is performed. The results show that the RMS of the PPP errors in X, Y and Z directions are about 0011 0, 0021 2 and 0009 5 m before APC correction, and about 0002 6, 0007 1 and 0003 7 m after antenna phase center correction, respectively. It can be seen that the positioning precision is improved obviously after APC correction. When the APC corrections are applied to the two receivers for the zero baseline common clock difference comparison, the standard deviation of the comparison results is decreased from 0148 2 ns before correction to 0093 0 ns after correction. For the long distance precision time comparison, the standard deviation of the comparison results is decreased from 0302 9 ns before correction to 0266 8 ns after correction. Therefore, with the construction of the BeiDou system and the continuous improvement of related BeiDou precision products from international GNSS service (IGS) analysis center, the service precision of BeiDou will be better and better.