Seven oleanene triterpenes were isolated from the roots of Potentilla discolor Bge and their structures were identified as 3-oxoolean-12-en-27-oic acid(1), gypsogenic acid(2), 3α-hydroxyolean-12-en-27-oic acid(3), 3β-hydroxyolean-12-en-27-oic acid(4), aceriphyllic acid A(5), aceriphyllic acid A methyl ester(6), and oleanolic acid(7). Compounds 1–7 inhibited protein tyrosine phosphatase 1B(PTP1B) activity, with IC50 values ranging from(7.5±0.5) to(22.7±0.5) μmol/L. Among the isolates, compounds 1, 2, 3 and 7 from the Potentilla discolor Bge were found to exhibit selective PTP1 B inhibitory activity.