The results of determination of soil samples indicated that soil soluble phosphorus measured by Olsen method was positively correlated to that by ASI method.The equation was Y=0.211 1+0.406X（R^**=0.917 8）.This indicated that both could be used as basic data in recommend of phosphorus application.The results of field trial showed that both phosphorus application amounts for the maximum benefit and yield were negatively correlated with soil soluble phosphorus.The equations were Y=100.16-1.250 6X（R^**=-0.800 2） and Y=117.47-1.296 6X（R^**=-0.764 2）.According to these two equations and determined soil soluble phosphorus,the optimal phosphorus application for maximum benefit and maximum yield could be proposed.