Protein tyrosine phosphatase 1B (PTP1B) is predicted to be therapeutic target in treatment of type 2 diabetes and obesity. Thus, in order to search for PTP1B inhibitors, we screened the inhibitory activity of PTP1B in the water extracts of 84 medicinal herbs. Among them, the extracts of Pini Folium, Magnoliae Cortex, Artemisiae asiaticae Herba, Schizonepetae Herba, Menthae Herba, Mume Fructus, Cimicifugae Rhizoma, and Amomi Cardamomi Fructus showed relatively significant (58-68%) inhibitory activity against PTP1B. Especially, the methylene chloride fraction of the methanol extract of Menthae Herba (81% inhibition at 30 ${mu}g$/ml) showed more potent inhibitory activity against PTP1B than others.