Abstract: Rainfall data from 1960 to 2005 was collected and analyzed to find the change trend and to estimate the crop water requirement. Field experiments were conducted at Luancheng Agro-ecology Experimental Station from 1996 to 2005 to calculate the soil water consumption. The results present 5.1mm/a rainfall decrease during last 46 years, especially in the summer maize growing periods. The water requirement of winter wheat is 2 times of that of summer maize. The field experiment shows that the crop yield is significantly related with rainfall in rain-fed area, and the crop yield does not varies obviously under water-saving irrigation. The rational irrigation should be taken in the future.