Abstract: Objective:The influence of isomaltooligosaccharide were tested for long bifidobacterium and lactobacillus acidophilus growth in vitro, and research as well as the influence of BALB/c mice intestinal runchang purge role for Constipated mice.Methods:by using different concentrations of isomaltooligosaccharide with glucose as carbon source in the culture medium, compared with only glucose as carbon source, detection under the condition of different concentrations of isomaltooligosaccharide long growth situation of bifidobacterium and lactobacillus acidophilus.In vivo experiments to BALB/c female mice as experimental object,giving mice with high dosage continuous(1.0 g/(kg·bw)),low dose(0.5 g/(kg·bw)) before and after 14 days of isomaltooligosaccharide, determination of bifidobacteria in mouse droppings, lactobacillus, enterobacter and enterococcus content.Continuous give high and low doses of isomaltooligosaccharide in mice after 21 days,to compound diphenoxylate Constipated mice model was established,and determined to give isomaltooligosaccharide Constipated mice after the row of the first black black time,6 hours and weight and small intestinal propulsion rates.Results:the in vitro experiment,compared with the carbon source is glucose,concentration of carbon source for different isomaltooligosaccharide and glucose,long the number of bifidobacterium and lactobacillus acidophilus increased significantly.In vivo experiment, the experimental mice stomach isomaltooligosaccharide after 14 days, compared with normal group, lactobacillus and bifidobacterium in excrement and urine were significantly increased,B/E value also increased significantly,and low dose group of intestinal bacteria in significantly reduced. Lavage itself, compared before and after the number of lactobacillus and bifidobacterium also increased significantly.After lavage isomaltooligosaccharide Constipated mice, the first row of black time shortened obviously, obviously increase the total row of black and small intestinal propulsion rates increased significantly.Conclusion:under the culture condition in vitro,isomaltooligosaccharide can increase the number of bifidobacterium and lactobacillus acidophilus.Isomaltooligosaccharide is improve mice gastrointestinal flora and runchang purge efficacy.