A novel single ended fault location algorithm based on the initial reverse polarity traveling wave（RPTW）detection is proposed. Research shows that the RPTW has less influencing factors，which ensures the high detection reliability，moreover， the time when the RPTW arrives has a certain relationship with fault location，has a piecewise linear characteristic. According to the characteristics of RPTW and combining the initial traveling wave，the fault section and the primary fault location can be determined as soon as the initial RPTW can be identified. After that the exact fault point will be located using other fault information contained in the single ended traveling waves. Only the initial traveling wave and initial PRTW have been used in the present algorithm，which will guarantee the detection accuracy. Simulation results show that the proposed algorithm can effectively locate the fault point，and obviously improve the single ended fault locations reliability and accuracy.