Abstract: In this paper we deal with the problems in the calculation of ocean loading effects (M2) on gravity tide and its space distribution in continental China.A calculating method is proposed in which the elevation of the calculated station is taken into account. The facter n must be transformed in theory so that the gravitational force term will have the same speed of convergence as the elastic term and the error |2fH*| is eliminated naturally. The method is further studied so that it combines the integral and approximation methods. The relation between the truncation angle 0 and the approximation order m are determined. The best way is: 0= 12 and m = l7. Effects of ocean loading on gravity tide of 200 points in China are calculated. The space distribution of the effects are given and discussed.