OBJECTIVE:To improve the method for the determination of 2 main components in Ticarcillin disodium and potas-sium 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 wave-length 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=0.9999) and 0.12-12.18 μg/mL for clavulanate(r=0.9999);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.