OBJECTIVE：To establish amethod for simultaneous determination ofbenzoic acid， methylis salicylas and thymol in Compound thymol solution.METHODS：HPLC was performed on the column of Thermo Hypersil BDS C18 with the mobile phase ofacetonitrile-water-acetic acid （40 ∶ 60 ∶ 0.02，V/V/V）at a flow rate of 1 ml/min， the detection wavelength was 275 nm， column temperature was 30 ℃， and injection volume was 10 μl. RESULTS：The linear range was 0.045 2-0.9030 mg/ml for benzoic acid， 0.0492-0.9844 mg/ml for methylis salicylas and 0.046 4-0.927 0 mg/ml for thymol； RSDs of precision， stability and reproducibility tests were lower than 2％； recoveries were 98.40％-108.88％（RSD＝3.26％，n＝9），98.21％-104.07％（RSD＝1.87％，n＝9） and 96.83-107.09％（RSD＝3.33％，n＝9），respectively. CONCLUSIONS：The method is simple， accurate and specific，and accurately determine the contents of benzoic acid，methylis salicylas and thymol in Compound thymol solution.