Abstract: Dry season is the critical period of ecological base flow in water shortage areas. Ecological base flow in dry season has several functions: eco-environmental function (avoiding dried-up river, maintaining wetland ecosystem, water purification, and nutrients transportation), natural function (sustaining hydrologic cycle), and social function (offering fishery production, entertainment and landscapes, and improving life quality). The values of these functions could be calculated using the method of natural resources and environmental economics, and then their sum is the total value of ecological base flow. To verify and demonstrate such a method, we have taken a case study of the Linjiacun hydrologic station on the Wei River. The results showed that, of the functions of ecological base flow in the Baoji reach of this river in 2010, the value of eco-environmental function (675.17 million yuan) was higher than that of natural function (154.63 million yuan) which exceeded the value of social function (121.99 million yuan). And the total value of 951.79 million yuan was calculated, for the value of unit ecological base flow 12.56 yuan/m3.