Abstract: OBJECTIVE To develop a quantitative method for simultaneous determination of andrographolide, deoxyandrographolide and neoandrographolide in Andrographis paniculata and Chuanxinlian injection by HPLC. METHODS A Shimadzu Shim-pack VP-ODS C₁₈ column (4.6 mm×150 mm, 5 μm) was used with CH3OH and water(53∶47) as mobile phase. The flow rate was 1 mL·min^-1, the column temperature was 25 ℃, the detection wavelength of andrographolide was set at 225 nm and the detection wavelength of deoxyandrographolide and neoandrographolide was set at 205 nm. RESULTS The 3 active components of diterpenoids were in baseline separation. The linearity of this method was good (r≥0.999 5), and the average recoveries were 99.6%-101.2%, RSD<3%. CONCLUSION The method is sensitive, accurate, reliable and repeatable, which can be used for quality evaluation of Andrographis paniculata and its injection, and for determination of 3 active components of diterpenoids quickly.