Abstract: By using the mathematical model of fractal insertion, an algorithm is given for auoustic logging curve based on similar logging data. When applying it to processing of the data of 7 similar logging in Dan Feng Chang, Sichuan and 3 similar logging in Nan Hai, the obtained fractal curve is very close to the real acoustic logging curve, with correlation coefficient greater than 70%. This method makes it possible to get the same message of logging curve from the CDP recording of the seismic prospecting.