Herb extracts commercially used in Korea were screened for PPAR-γ agonist test and α-glucosidase inhibition assay. Total 16 herb plants had a PPAR-γ agonist activity. Specially, Alisma orientale Juz (108.41%), Ephedra sinica (98.22%), Sasa japonica Makino var. purpurascens Nakai (140.68%), Astragalus membranaceus Bunge (106.79%) and Cnidium officinale Makino (113.00%) showed high PPAR-γ agonist activity rate compared with rosiglitazone's (167.46%). And Cornus officinalis S. et Z. (90.3%), Cinnamomum cassia Blume (89.2%), Psoralea corylifolia L. (89.8%), Paeonia japonica (Makino) Miyabe (92.4%) and Paeonia suffruticosa Andr (93.2%), showed high α-glucosidase inhibition rates. These results support previous reports of the efficacy of Oriental medicinal plants used for diabetes mellitus.