DN-108 (5-(4-(1-phenyl-1-cyclopropanecarbonylamino)benzyl)thiazolidine-2, 4-dione, CAS 195604-21-8) is a newly synthesized thiazolidinedione derivative. Pharmacological and pharmacokinetic studies of DN-108 were done. In diabetic animal models KKAy and db/db mice, DN-108, orally given at doses of 3-30 mg/kg for 10 consecutive days, improved hyperglycemia, hypertriglyceridemia or hyperinsulinemia from day 1 or day 4 and the effects were almost maintained through the experiment. In KKAy mice, DN-108, orally given at doses of 3-30 mg/kg for 4 consecutive days, potently decreased serum glucose level as compared with troglitazone (CAS 97322-87-7) and the ED25 values of DN-108 and troglitazone were 7 and 283 mg/kg/day, respectively. DN-108 increased 2-deoxyglucose uptake in L6 muscle cell line to the same extent as troglitazone. Moreover, DN-108 inhibited aldose reductase activity in vitro as potently as troglitazone did. Pharmacokinetic parameters, Cmax and AUC of DN-108 after oral administration in rats were higher than those of troglitazone. These results suggest that DN-108 has antidiabetic effect with tissue sensitization for glucose uptake and high absorption after oral administration. It is expected that DN-108 will be a promising oral antidiabetic agent.