The conventional automation fault section locating， which has traditionally been designed assuming the system to be radial is no longer suitable for the system with distributed generation（DG）. A new locating algorithm based on fault current signals is proposed in the paper， which first， the fault region search is with the search tree and the complex current criterion; secondly， a fault description matrix is constructed by using the high association nodes found in the first step. Then elicit the fault judgment matrix with Kirchhoff's law and principle of phase comparison for accurate locating of fault section. This algorithm is adapted to initial structure of the distribution network and the variation of DG，and improve sensitivity of protection by using the complex current. The validity of the new algorithms is verified by the result of an example.