Abstract: In the paper,Asp(approx imation after sor tand pair) method have been put forward forget parameters of rainfall estimate.The paper use 1314 samples of radar and 17 precipitation stations at 1993-1994.This method make up the defect of linear regression and raise the precision ofarea rainfall estimate.Having analysed the errors,have gained the result:When estimate area precipitation more than 1 000km2 using dual linear polarization radar,the error will redeced to under 10% probably,it is better more than conventional radar;The difference between estimate formulas of dual linear polarization radar can over look;The method of estimate area rainfall in classified parameters is only effective using conventional radar.