Kucha (Camellia assamica var. kucha) is an endemic tea that grows in cloudy and foggy highlands in southwest China. Its hypoglycemic effects were studied here. The postprandial blood glucose levels in mice after sucrose and soluble starch loading were significantly reduced by Kucha administration. The glycosidase inhibitory activities were effective both in vitro and in vivo. It is concluded that the hypoglycemic effects of Kucha might be due to inhibition of disaccharidases activities.