Abstract：Simulated fault parameter values are adopted to deduce the earth surface gravity changes with the combination model of vertical rectangular and the coordinate rotation theory. Numerical simulated experiments of gravity change distribution are conducted for the activities of the vertical fault disclination in a single direction and in two directions, respectively, at depths of 1 km, 5 km and 10 km. The conclusions show that the gravitational variation field shows symmetrical distribution when the vertical fault occurs with a disclination of W1 or W2 pattern based on the left point of the fault in a single direction. In addition, it appears that four quadrants show an antisymmetric distribution when a vertical fault occurs with a disclination of W3 pattern based on the midpoint of the fault. The gravitational variations field shows symmetrical distribution when the vertical fault occurs with a disclination of W1W2 pattern based on the left point of the fault. Moreover, the W2 pattern plays an important role. Gravitational variations field presents a symmetrical distribution when the vertical fault occurs with a disclination of W2W3 pattern based on the midpoint of the fault, with an obvious twisting phenomenon that is attributed to the disclination of W3 pattern in the fault vicinity. Overall, it also shows that the W2 pattern plays an important role. The earth surface gravity change is decreasing progressively when the depth of faults is increasing. However the region influenced by the vertical fault disclination is extending.
