Abstract: Based on the high precision data of gravity observation and GPS, we have obtained finer first derivative gradient in vertical direction and the normalized total gradient (G^H) image of Bouguer gravity anomaly in Yichuan-Tai'an profile. A further investigation on the vertical first derivative gradient characteristics is carried out with the results in literature, from which we could conclude that it mainly expresses the shallow source location and features of low density geological body. Using the G^H image, we also analyzed and explained the spatial distribution characteristics of seven major faults that the profile goes through and speculated the possible buried depths and properties of each fault.