The developmental toxicity of water extract of licorice (Glycyrrhiza glabra) was evaluated in rats. Licorice extract (500, 1,000 or 2,000 mg/kg) was dissolved in drinking water and orally administered to male rats from 9 weeks before mating to the day of copulation, and to females from 2 weeks before mating to gestational day 19. On gestational day 20, the animals were sacrificed for Cesarian section, and maternal and fetal abnormalities were examined. Licorice extract neither induce clinical signs, nor affect the body weight gain, feed and water intake, estrous cycle, copulation and fertility rates, blood $17eta-estradiol$ level and organ weights of dams. Also, the implantation and development including body weights, absorption and death of embryos and fetuses were not influenced by in utero exposure to licorice. In addition, there were no increases in external, visceral and skeletal abnormalities of fetuses. Taken together, it is suggested that no observed adverse effect level of licorice extract is higher than 2,000 mg/kg, and that long-term in utero exposure to licorice might not cause developmental toxicities of embryos and fetuses.