Objectives : To evaluate the safety of KOB, a polyherbal medicine for allergic rhinitis, we conducted a subchronic toxicology study. Methods : Dried extract of KOB(Lot. No. 11003, yield : 41.1%) was prepared from GLP company (Hanpoong Pharm & Food Co., Ltd). KOB was repeatedly administrated orally of male SD rats at daily dose levels of 500 (G2), 1250 (G3) and 5000 (G4) mg/kg/day for 13 weeks. We recorded the clinical signs of toxicity, body weight, food intake/consumption, optometry, urine analysis, organ weights, hematology, and conducted serum biochemical analysis, necropsy, gross and histological changes in target organs of Sprague-Dawley rats, and clinical chemistry analysis. Results : Neither death nor any toxicological signs were obserbed in KOB at all doses of 500, 1250 and 5000 mg/kg/day during the administration period for thirteen-week. Furthermore, there was no difference in body weight and food-take consumption, optometry, necropsy, organ weight, gross pathological findings, and urine analysis among the groups of rats treated with different doses of KOB, during at the observation period for thirteen-week. The hematological analysis and clinical blood chemistry data were revealed no toxic effects from repeated-dose administration of KOB in rats during the observation period. Conclusions : Based on these results, the no observable adverse effect level (NOAEL) of KOB was considered to be 5000 mg/kg/day for male rats under these study conditions.