Abstract:Gravity tide observation data plays an important role in the establishment of global tide model,and tide observation correction model,and the recognition of gravity disturbance signal. The accuracy of tide observation is critical to complete the above work. In this paper,the tidal model precision observed by 10 gPhone gravimeters in CMONOC have been compared to the existing ones. The effect of the observation environment and system,as well as the relationship between the accuracy of observed tidal model and of the tidal correction model have been discussed. It is shown that the accuracy of these gPhone gravimeters of which the optimal tide factor accuracy of M2 is 0.00014 and average one is less than 0.001,which is 0.5～1.0 order higher than in magnitude of the spring gravimeters in 1980～1990s. The accuracy of some gPhone can reach the level of early Superconducting gravimeters(SG). However,compared with of the OSG,the accuracy of gPhone is less than 0.5～1.0 order in magnitude. The tidal correction accuracy of the optimal tidal observation model in CMONOC is about ±(0.2～0.3)×10-8m/s2,which is higher than ±(0.3～0.6)×10-8m/s2 of DDW/NHi model. And the observed tidal correction model is better than the theoretical one in all of gPhone. The disturbance of the observation environment and system will decrease the accuracy of the observed tidal correction model. In specific,some accuracy have reduced from(0.1～0.2)×10-8m/s2 to(1.0～1.7)×10-8m/s2 by interference of the observation system.