The work aims to establish high performance liquid chromatography (HPLC) to determine the contents of three benzalkonium chlorides (dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl amm- onium chloride, hexadecyl dimethyl benzyl ammonium chloride) in packaging materials. Samples were extracted by methanol-water (volume ratio 1∶1) ultrasound and centrifugal filtration, determined by diode array detector, and quantified by external standard method. The results showed that three benzalkonium chlorides had good linearity in the range of 10.0~500.0 mg/L, and r2 were less than or equal to 0.9996; the detection limit was 2.5~5.0 mg/L; the limit of quantification was 10.0 ~20.0 mg/L; the average recovery rate was 88.7%~96.6%, and the relative standard deviation was 2.5%~5.3%. The pretreatment of the proposed method is simple, and it is of high sensitivity and accuracy.