Abstract: The geochemical logging technology developed in recent years is a new method for evaluation of hydrocarbon-bearing features of reservoirs. The features of logging interval of well Xiang 9 in Xiangcheng sag are restudied in this paper. On the basis of analysis of geochemical parafneters to detritus dry samples,it was pointed out that Xiangcheng sag is in good oil - generating and oil - trapping condition. Because of the northen slope in the sag is adjacent to the generating area,it has a good exploration potential.