OBJECTIVE： To improve the method of content determination of salvianolic acid B in Salvianolate injection. METHODS： HPLC method performed on the column of Hypersil ODS C18 with mobile phase of methanol-acetonitrile-methanoic acid-water （30 ∶ 10 ∶ 1 ∶ 59，V/V/V/V） at a flow rate of 1.0 ml/min， detection wavelength was 286 nm， column temperature was 25 ℃， and injection volume was 10 μl. RESULTS： The linear range of salvianolic acid B was 0.1-3.2 mg/ml（r＝0.999 6）；RSDs of precision， stability and reproducibility tests were lower than 2％； recovery was 98.15％-100.23％（RSD＝0.58％，n＝9）. CONCLUSIONS： The improved method is more sensitive and reproducible， and suitable for the content determination of salvianolic acid B in Salvianolate injection.