The analysis of summer precipitation anomaly and the feature of water vapor transport in Qinghai Plateau for the last 43 years is made. It shows that (1) The summer precipitation increased at first and then decreased. After the end of 1980's, precipitation has a steady cycle of three-year, and is in a rainy period now. (2)The content of water vapor flux in Qinghai plateau varies from 50 to 150kg·m^-1·s^-1, and it increases from west to east boundary. The net vapor flux has an increasing tendency in the last 43 years. (3) In a dry year, water vapor flux decreases about 10—40kg·m^-1·s^-1, and there is a increasing vapor flux divergence field. In a moist year, the water vapor flux increases about 10—20kg·m^-1·s^-1, and there is a increasing vapor flux convergence. (4) In a dry year, the net water vapor flux is positive always, but the content is low about 21.88% than average state, and it is high about 53.99% in a moist year.