This paper presents a method of single ended fault location for distribution network based on estimated contralateral information. This method is based on time-domain distributed parameter line model and 0, 1, 2-mode network, according to the head-end sampling information, firstly calculates mode voltage of the failed port and mode current which flows from the first end to the fault branch, then estimates the voltage and current information of the end by the mode voltage of the failed port, and then gets the mode current which flows from the end to the fault branch, establishes ranging function by using the boundary condition about the fault branch 0, 1, 2-mode current equal to the instantaneous value, and through the search method, finally achieves fault location. The proposed algorithm can take advantage of both transient and steady state volumes after a fault for distance caculation by requiring only a single ended of sampling information, and unaffected by distribution network branch, transition resistance, fault location and the neutral point operation mode and other factors. A large number of EMTP simulation results show that the algorithm is accurate and applicable.