中文摘要：

估计和比较GPS和GRACE得到的地表垂直负荷形变，发现全球大部分地区，扣除GRACE地表位移后GPS垂直坐标时间序列均方根（RMS）减小，而且二者周年变化的相位和振幅大部分地区具有较好一致性，反映GPS高程非线性季节性变化主要是由地表质量负荷引起的。然而在某些区域，特别是南极洲、海岸带附近和小岛屿，二者之间存在较大的偏差。分析和讨论两种技术中可能引入的各种误差源及其影响得出，GRACE负荷形变估计影响较小，这与地球物理模型估计的一致性得到了验证，因而剩下偏差是否由GPS本身技术误差所引起，还有待新的高分辨率重力卫星和更多GPS观测和新模型的进一步研究。

英文摘要：

We computed at most global sites, the root and compared the vertical loading deformation from GPS and GRACE and found that mean square （RMS）of GPS coordinate time series decreased after removing the GRACE estimates, and the annual variations of the GPS height at most sites also agree well with GRACE or geo- physical model estimates in the amplitude and phase. It indicates that the nonlinear seasonal GPS vertical variation is mainly caused by the geophysical loads. However, at some sites, particularly in the Antarctica, some ocean coasts and small peninsulas, large discrepancy has been found between the estimates with the two techniques. We analyzed and discussed the error sources of the discrepancies between GPS and GRACE and their effects, which is proved by a good agreement with geophysical models, and the remaining disagreement may be due to the GPS tech- nical errors. It needs to further investigate using longer and more GPS and GRACE measurements.