Abstract: Through correlation analysis of temperature, heat and wheat yield in Shaanxi province, an optimum regression model of them is established. It's indicated that in less precipitation areas of this province, the yield-increasing effect of temperature and heat is not normally brought into play, but in more precipitation areas, this effect brings into paly to a certain extent. Corresponding yield-increasing measures for wheat in various areas of this province are put forward in this paper.

Key words: Temperature and heat, Wheat yield, Optimum regression model, precipitation deficit., cotton water requirement, rainfall insurance rate