In order to understand the content of benzoic acid and potassium sorbate in raw milk, the content of benzoic acid and potassium sorbate in samples of different sources incluing raw milk, whole milk powder and infant formula were determined. The results showed no potassium sorbate existed in any of the samples. The average content of benzoic acid in 20 samples of raw milk was 5.02 mg/kg, the average content of benzoic acid in 30 samples of whole milk was 33.76 mg/kg, the average content of benzoic acid in 30 samples of infant formula was 23.3 mg/kg. These results may be served as a reference fo...