Objective: To study and improve the quality standard of Hypericum japonicum with isoquercitrin and quercitrin as index. Method: TLC was used for qualitative identification method. Quercitrin and isoquercitrin were determined by HPLC. Result: The TLC spots of isoquercitrin and quercitrin were clear

well separated; the results of 10 batch of H. japonicum from different area were consistent. Average content of isoquercitrin was 0.4%

the average content of quercitrin was 0.5%; the recovery of isoquercitrin was 99.39% with RSD of 1.85%

and the recovery of quercitrin was 98.98% with RSD of 2.76%. Conclusion: Qualitative and quantitative methods are rapid

accurate

with strong specificity and good reproducibility

which can be used for the quality control of Hypericum japonicum.