In this paper, the authors propose a determination method of optimal allocation and transfer of step voltage regulators (SVRs) in distribution feeders with renewable energy sources (RES). The feature of the proposed method is to determine optimal allocation and transfer of SVRs based on the forecasted amount of PV introduced to distribution feeders a few years later and cooperative controlling of SVRs and LRT. In the proposed method, voltage margin is maximized under a constraint that all the node voltages are controlled within the proper range for a certain period of years. In order to verify the validity of the proposed method, the optimal allocation and transfer of SVRs obtained by the proposed method is compared with the optimal one of the conventional approach. In the numerical simulation results, the number of transfer and install of SVR with the proposed method is reduced from those of conventional method.