Inulo-oligosaccharides were produced from inulin with high yield by using a purified endoinulinase from a commercial inulinase preparation. The maximum yield of oligosaccharide achieved was around 96% irrespective of substrate concentrations ranged from 50 to 150 g inulin/l. A wide range of degradation products from inulin, varying in their DP (degree of polymerization) 2 to 6, were obtained where the major oligosaccharides were DP3 and 4. The reaction pH gave rise to a significant difference in yield and sugar composition of inulo-oligosaccharides.