| According to the statistical data of grain production in Shaanxi Province in the year of 19832002,the non-linear regression model of grain production was established by using Cobb—Douglass production function in the software environment of SPSS.It was used to predict the mid and long term situation of grain supply and demand equilibrium,being combined with the grain demand structure model.On the basis of simulating the fluctuation tendency of grain production,the criterion of grain security line was brought forward and the security situation in Shaanxi Province was evaluated.The results show that the grain supply and demand in Shaanxi Province is basically balanced,but since 2000,the amount of residual grain has been decreasing generally and the security situation has been descending;the security line of the lowest grain planting area is about 2.30×106 hm2; the amount of grain deposit in the farmers' households has been under the security level for a long time;the security line of grain deposit should be about 690(kilo-tons.) |