OBJECTIVE： To improve the method for the determination of 2 main components in Ticarcillin disodium and potassium clavulanate for injection. METHODS： HPLC was performed on the column of Waters XBridgeTM C18 with mobile phase of  0.01 mol/L ammonium dibasic phosphate solution （pH 7.0）-menthol （80 ∶ 20，V/V） at a flow rate of 1.0 mL/min， the detection wavelength was 220 nm， column temperature was 30 ℃， and injection volume was 20 μL. RESULTS： The linear range was 1.95-195.22 μg/mL for ticarcillin （r＝0.999 9） and 0.12-12.18 μg/mL for clavulanate（r＝0.999 9）； RSDs of precision， stability （under 4 ℃） and reproducibility tests were lower than 1.0％；recoveries were 99.3％-100.5％（RSD＝0.4％，n＝9） and 99.2％- 101.0％ （RSD＝0.7％，n＝9）. CONCLUSIONS： The method is rapid， accurate and reliable， and can be used for the determination of 2 main components in Ticarcillin disodium and potassium clavulanate for injection.