Abstract: To reduce the effect of instability in outputs of wind farm and solar power, complementary operation modes of them together with hydropower are presented in this paper. We chose three typical power stations on the upper Jinsha, namely the Dechang wind farm, Wanjiashan solar power station, and Gangtuo hydropower station, and analyzed their power output features and complementarity at time scales of a day, a month and a year. A real time model of complementary operation was developed and coded in visual basic and then applied to calculation of reservoir operation modes under the condition that the total power grid load, wind power output and photovoltaic output were all known. The results show that a complementary operation mode of merging three types of outputs before connected to the power grid can lower the negative impact of instable wind and solar power and improve power transmission efficiency, thus showing a great significance in improving the environments and energy structure.