Yaowang tea, the leaves and flowers of Potentilla glabra Lodd. (family Rosaceae), has been used for a long time to prevent and mitigate hyperlipidemia, hypertension, diabetes and so on. According to this research, twelve flavonoids were isolated and all the flavonoids were obtained for the first time in P. glabra. The different polar portions (petroleum ether portion, ethyl acetate portion, n-butanol portion and water portion) and six flavonoids from P. glabra were screened, and their antioxidant abilities were measured by DPPH and FRAP assays. Six tested flavonoids showed significant free radical scavenging capacity in the DPPH assay and total antioxidant activity in the FRAP assay compared with Vitamin C (Vc). This work provides an understanding for the flavonoids of P. glabra and lays the foundation for the future research.