In this paper, the authors investigated the fault structure of TANA sag in Kenya by means of new techniques for geophysical source boundary detection using potential-field data. The result indicates that the inversion of gravity data based on the combination of the TDR, THDR, Theta map and Euler deconvolution is an effective method for fault identification, and could show the position and depth more accurately and clearly than traditional method. This work will provide new method and be of use for further exploration on geology, oil and gas in this area.