目的 测定不同产地浮萍Spirodela polyrriza中5个黄酮类成分的量，并对其抗氧化活性进行评价。方法 采用HPLC法，以乙腈-0.1%甲酸为流动相测定8个产地17批浮萍药材中荭草素、牡荆素、木犀草苷、大波斯菊苷、木犀草素的量；采用DPPH清除率法比较不同产地浮萍的抗氧化活性，并结合聚类分析和主成分分析等化学模式识别技术对浮萍质量进行评价。结果 不同产地浮萍中5个黄酮类成分量存在一定差异，聚类分析和主成分分析均可将不同产地浮萍分为3类，且分类结果一致。其中陕西和山西产地的浮萍中荭草素、牡荆素、木犀草苷的量均较其他产地明显偏高；相关性分析表明，氧化清除率与黄酮类成分量呈显著正相关。结论 陕西和山西产地的浮萍黄酮类成分量高，抗氧化能力较强。所建立的分析方法稳定可靠，可为浮萍药材的产地识别和质量控制提供参考。

Objective To determine the contents of five flavonoids in Spirodelae Herba from different growing areas, and evaluate its anti-oxidant activity. Methods Contents of orientin, vitexin, cynaroside, apigenin-7-glucoside, and luteolin in 17 batches of Spirodelae Herba from eight origins were determined by HPLC with acetonitrile and 0.1% formic acid as mobile phase, and DPPH method was used to compare their anti-oxidant activities, together with cluster analysis and principal component analysis, the quality of Spirodelae Herba was evaluated. Results The contents of five flavonoids in Spirodelae Herba from different growing areas exist certain differences, which can be divided into three different categories by cluster analysis and principal component analysis. The contents of orientin, vitexin, and cynaroside were significantly higher in samples from Shaanxi and Shanxi provinces than those from other origins, as well as their oxidation clearance rates were relatively high. The correlation analysis showed there was a significant positive correlation between the rate of oxidative elimination and flavonoid content. Conclusion Spirodelae Herba from Shaanxi and Shanxi provinces has higher contents of flavonoids with strong antioxidant capacity. The analytical method is stable and reliable, which can provide the reference for enhancing the quality control of Spirodelae Herba.