Abstract: In this study, the total flavonoids from Huai Chrysanthemum were extracted by subcritical water and examined by visible spectrophotometry, while antioxidant activity of the total flavonoids was also determined, and the response surface method was used to optimize subcritical water extraction of total flavonoids in Huai Chrysanthemum. Firstly, single factor experiment was investigated, and then based on single factor experiment, a 3-factor, 3-level Box-Benhnken experiment was designed, in which extraction temperature, time and the ratio of solid to liquid were chosen as influencing factors, and the yield of total flavonoids was selected as response value. The optimum conditions of subcritical water extraction were extraction temperature of 130℃, extraction time of 46 min and liquid to solid ratio of 44:1, and the predicted value of flavonoids extraction yield was 71.806 mg/g, which was in consistent with the measured value of (71.796±0.24) mg/g. The results showed that the flavonoids obtained from the material had some antioxidant activity, and an excellent correlation between antioxidant properties and total flavonoids content was observed.