Objective:To establish an HPLC method for determining the content of juglone in the husk of walnut

to provide the basis for the resource exploitation and utilization of juglone.Method:The method was evaluated by HPLC in methodology and the samples which were fresh and stored in freeze temperature were determined.Result: This HPLC methord have a simple preparation for popularization easily.The results indicate that this certain method had good linear relationship under the condition that the content was between 0.01 μg and 8 μg（r=0.999 3） and the detection limit of this method was 0.195 ng.The average recovery was 98.67%（n=6）

RSD was below 2.03%;the RSD of the indicated accuracy was below 0.58%（n=7）.Juglone in the husk of fresh walnut was 1.66 mg·g-1 and another sample was 1.54 mg·g-1 which was stored in freeze temperature.Conclusion: This certain method is simple

fast and reproducible with a high accuracy and precision

which fit for the analysis of juglone.