Abstract: A GF-AAS method based on using the organic reagent as matrix modifier was proposed for the determination of lead in urine.Tartaric acid solution was added into urine for the reduction of atomization temperature from 150 0 ℃ to 1 200 ℃ and elimination of matrix interferences.By the addition of NH4H2PO4 the values of absorbance measured were significantly increased.Detection limit (3S/N) of the method was 30 pg and recovery was ranged in 99.1%-102.6%,with RSD (n=6) less than 6%.