Abstract: Oligosaccharides were extracted from two cultivars of bananas( Musa AA Pisang Mas and Musa ABB Pisang Awak)separately,and 2 dose groups 2.5 g /( kg·BW·d) and 1.25 g /( kg·BW·d) were set up for each variety.According to“Handbook of Technical Standards for Testing and Assessment of Health Food in China”,the laxative effects of banana oligosaccharides( BOS) were studied. Results showed that the ink- impelling ratio of the small intestine in four BOS- dose groups was significantly greater than that in the model group,and the time of the first ink defecation was shorter than that in the model group significantly,suggesting that two BOS doses of two banana cultivars were effective in facilitating bowel movement. The difference between four dose groups was not significant.Effects of BOS on dejecta moisture content and small intestine moisture content showed no significant difference,indicating that defecation functions caused by BOS was not based on increasing the moisture content of dejecta and small intestine possibly.