Objective To establish a method to analyze the composition and content of monoses in the garlic polysaccharide by ion chromatography. Methods The monoses in the solution of garlic polysaccharide hydrolysised by trifluoroacetic acid were determined by amino PAC column, eluted by gradient hydroxide sodium and identified by ampere detector (AU as working electrode, Ag/AgCl as reference electrode). Results The garlic polysaccharide was mainly composed by arabinose, galactose, glucose, xylose and fructose. Good resolution could be achieved among the above mentioned five kinds of monoses. Their linear correlations over the investigated concentration were above 0.998, while the average recovery rates were in the range of 95%-105%. Conclusion The ion chromatography method is fast, accurate, simple and reliable, and can be applied in the content determination and quality control of garlic polysaccharide.