Type 2 diabetes is characterized by an inability of the endocrine pancreas to secrete sufficient insulin to meet the metabolic demands associated with insulin resistance and obesity. Both insulin resistance and β-cell dysfunction are key elements in the pathogenesis of this disorder. Thiazolidinedione (TZD) is an oral hypoglycemic agent for the treatment of type 2 diabetes targeting insulin resistance. TZD is the only pure insulin sensitizer that enter the cell and bind to the peroxisome proliferator-activated receptor-γ (PPAR-γ), a nuclear receptor found predominantly in adipocytes, but also in muscle and liver, forming a complex with the retinoid X receptor (RXR). Binding of a TZD to PPAR-γ leads to enhanced expression of certain insulin-sensitive genes that regulate glucose and fat metabolism. Thus, glucose uptake and lipogenesis in adipocytes increase, while circulating fatty acids concentrations decrease. Lobeglitazone, a newly developed TZD by Korean pharmaceutical company (Chong Kun Dang Inc.), can be prescribed recently in Korea. This new noble drug can contribute to treat insulin resistance of type 2 diabetic patients.