The objective of the paper was to establish a method for high performance liquid chromatog. determination of salvianolic acid B in Naotang granula. The condition for high performance liquid chromatog. was Diamonsil C18 column (250 mm × 4.6 mm, 5 μm) with methanol-acetonitrile-formic acid-water (30:10:0.5:59.5) as the mobile phase. The flow rate was 1.0 mL/min. The column temperature was 40°. The injection volume was 10 μL, and detection wavelength was 286 nm. Results showed that the linear range was of 0.441 6-2.208 0 μg for salvianolic acid B and the correlation coefficient was 0.999 7. The average recovery was 98.65% with RSD 1.71%. It was concluded that the method was reproducible, reliable, and can be used for quality control of Naotong granula.