The harmonic series formula of the Earth´s disturbing potential is the most extensive applicable expression for the Earth´s gravity field model. At present, the resolution of the used geopotential coefficient model is 0.5°, and the complete degree and order is 360. Since the gravity data density and precision are very different everywhere, the model accuracy isn´t uniform. The improvement of model is necessary.. The method of the regional correction with frequency weight for improving a known model is a convenient and applicable method. Based on the OSU91A and EGM96 models and regional 15´×15´ △g and 5´×5´ △g, the improved models DQM99A and DQM99B to degree 720, DQM99C and DQM99D to degree 2 160 are developed. Their accuracy comparison is presented in this paper.