This paper proposes a novel method to search the optimal topology of radial distribution network which maximizes total output power of photovoltaic generators (PV) on the network and keeps the network voltage within a regulated range. The method is based on a correlation between total PV output and the largest difference in the voltage profile and the principle of superposition for the radial network. The optimal topology is found out so as to form a tree by extending distribution feeders from a distribution substation. In order to verify the effectiveness of the method, a comparison study with tabu search approach was carried out by using a multi loop distribution network model. The result shows that the method can find a suboptimal topology faster than tabu search.