Based on the gravity model of variable density combinational body, theauthors have developed the method and program for automatic fitting of gra-vity curves.The advantage of this method lies in the fact that it utilizes theknown geologic and geophysical data to the maximum extent, and thus canovercome the interference by man in the process of man-machine interaction;in addition, as a result of progressive modification of the thickness,width anddensity for various layer sections during the curve fitting, the computationand fitting are carried out as a whole, so that the calculation precision canbe greatly raised. No operator is required in the course of computation, andhence the purpose of saving time can be attained.