Abstract: In addition to the main content of phosphorus，yellow phosphorus products also contain other impurities，such as organic impurities，arsenic，lead，sulfur and so on.In order to resolve the interference of organic matters in determining the phosphorus content based on the current National Standard，exploration disclosed that phosphomolybdic acid quinoline gravimetric method can be applied in the determination of phosphorus content in the yellow phosphorus.The method uses the mixed acid to dissolve yellow phosphorus sample and through further hydrolysis to let the phosphorus in the sample transform into phosphoric acid completely.Then figure out the mass of quinoline phosphomolybdate through analysis.Finally，the elemental phosphorous content can be calculated according to the mass of quinoline phosphomolybdate.From the analysis of data obtained，the reliability of the method is in a high degree and it can be applied in phosphorus content determination.With additional analysis，the inspection of other trace impurities could also be settled at the same times.