Abstract: Experiments to investigate the effects of daidzein on membrane digestion of disaccharide in suckling and weanling piglet were carried in vitro. 12 piglets were randomly assigned two groups， either supplemented with 20mg/kg·BW daidzein or skim milk powder once per two days after birth one week. 14 and 35 days old piglets were killed, jejunum and colon were collected for further study.The result showed that supplemented with daidzein can improve the activities of maltase and lactase in jejunum mucosa and colon mucosa in the lactational period of piglet, the activities of maltase and lactase in jejunum mucosa increased by 63.30%（P＜0.01）and 49.98%（P＜0.01）, and those in the colon increased by 56.78%（P＜0.01）and 24.05%（P＜0.01）respectively. However, in weanling piglets the activity of lactase was decreased by 41.40%（P＜0.05），whereas the activity of maltase increased by 22.31%（P＜0.01） in jejunum, the activity of maltase increased by 21.14%（P＜0.05）in colon. This result indicates that feeding daidzein can improve the using of disaccharide in piglets.