The paper presents a fault location algorithm that takes the transmission line parameters, the asynchronous sampling error angle between two-terminal and fault distance as unknown variables. The voltages and currents during fault at two-terminal are assumed to be available. The unknowns can be obtained by utilizing the Newton-Raphson approach to solve the nonlinear equations. The result of fault location expressed by the percentage corresponding to the ratio of fault distance to whole-length of transmission line can avoid the error produced by the transmission line length that changes with temperature. It is convenient to find the fault point by the location of the towers on the line. The proposed algorithm avoids the fault location error caused by inaccuracy of line parameters. Simulation results show that high accuracy of fault location can be obtained by use of the proposed algorithm.