Objective： In this study， we use high-throughput sequencing to investigate the regulation of oligosaccharides with different monosaccharide composition on the human gut microbiota. Methods： Simulator of the human intestinal microbial ecosystem was used to study the modulation of polydextrose， polygalactose and polymannose on gut microbiota from human feces. After 0-， 12- and 24-hours in vitro fermentation， gut microbiota was obtained for composition analysis by 16S rRNA genes sequencing， and the supernatant was separated for short-chain fatty acids （SCFAs） analysis. Results： Polygalactosel （PGal） produced the most amounts of SCFAs in all three oligosaccharides， followed by Polydextrose （PDX）， and Polymannose（PMan） coming in third. PGal consisted of galactose is more beneficial to the production of acetic acid and propionic acid， and inhibit the growing of harmful bacteria Blautia and Dorea. PDX consisted of glucose is more beneficial to the production of butyric acid and valeric acid， inhibit the growing of harmful bacterial Collinsella， and promote in the proliferation of Bifidobacterium， Parabacteroides and Streptococcus. PMan consist of mannose inhibit the growth of Ruminococcus. Conclusion： All three oligosaccharides could modulate gut microbiota and produce SCFAs. Further promote the proliferation of beneficial bacteria and inhibit the growth of harmful bacteria.