Insulin sensitizing medicines are currently limited, and identification of new drug candidate is a challenge.Protein tyrosine phosphatase 1B (PTP1 B) negatively regulates insulin signaling pathway, and its inhibition is anticipated to improve insulin resistance.This study investigated the pharmacological profiles of compound CX08005, a new PTP1 B inhibitor, with therapeutic potential for insulin resistance in vivo and in vitro, respectively.Recombinant human PTP1 B protein was used to measure the enzyme activity.The docking simulation was performed to explore the interactions between the compound and the protein.The insulin sensitivity was evaluated in Dietinduced obesity mice and/or T2DM KKAy mice by glucose tolerance test (GTT), the blood glucose level,glucose stimulated insulin secretion (GSIS), homeostasis model assessment of insulin resistance index (HOMAIR) and the wholebody insulin sensitivity (Iswb) index, respectively.The hyperinsulinemieeuglyeemie clamp was performed to evaluate the insulin stimulated glucose disposal both in whole body and in insulinsensitive tissues(muscle and fat).Furthermore, its direct effect in muscle, fat and liver cells was observed.We found that CX08005 was a competitive inhibitor of PTP1B with dosedependent activity (IC50 =5.95 × 107 M).Docking simulation demonstrated that CX08005 binds to PTP1B at the catalytic Ploop through hydrogen bonds.In DIO mice, treatment with CX08005 effectively ameliorated glucose intolerance in a dosedependent manner (50 ~200mg · kg1 · d1), and decreased HOMAIR values.We also demonstrated that oral administration of 50 mg ·kg1 · d1 CX08005 improved hyperglycemia, hyperinsulinemia, HOMAIR and Iswb in KKAy mice.In hyperinsulinemiceuglycemic clamp test, CX08005 increased glucose infusion rate and glucose uptake in muscle and fat of DIO mice.In 3T3L1 adipocytes and C2C12 myotubes, CX08005 enhanced insulininduced glucose uptake.In HepG2 hepatocyte, CX08005 enhanced insulinstimulated tyrosine phosphorylation of Irβ/IRS1 in a dosedependent manner, respectively; furthermore, the phosphorylation of several downstream molecules, including Akt, Foxo1and GSK3β was also increased, indicating this compound could augment insulin s ability to suppress hepatic glucose output (HGO).Our results strongly suggest that compound CX08005 directly enhances insulin action in vitro and in vivo with therapeutic potential for insulin resistance.