Abstract:Using the improved analytic hierarchy process, variation coefficient method and combination weighted methods, the impact weights of drought to the yield of winter wheat in main growng stage after winter was determined. During 2002 to 2009 in Five Cities of Guanzhong Plain, a linear regression model of annual weighted VTCI to the yield of winter wheat was established and analyzed the linear relation of VTCI with yield. The results showed that the linear relativity of weighted VTCI to yield of winter wheat determined by the variation coefficient method was not remarkable, the dicision coefficient R² value was total less than 0.5 in Weinan, Xianyang and Tongchuan. But the linear relativity of weighted VTCI to yield of winter wheat determined by the improved analytic hierarchy process and combination weighted method was remarkable, and the R² values of the Four Cities except Tongchuan was close to 0.5 or larger than 0.6, and the R² values in Xian by the combination weighted method was larger than 0.7. The results of improved analytic hierarchy process and variation coefficient method was better than the combination weighted method, so they were the good methods and can be used to evaluate the drought monitoring effects in the main growing period of winter wheat.