Four banana cultivars in 1st-7th ripening states were chosen as raw materials. They were Musa AAA Cavendish, Musa ABB Pisan Awak, Musa AA Pisang Mas and Musa ABB Bluggoe. The ultrasonic-assisted method was used to extract banana oligosaccharides and the oligosaccharide contents were determined. Sephadex G-25 column chromatography was used to separate and purify banana oligosaccharides. Results showed that the content of banana oligosaccharides of four varieties increased with the increasing maturity. Therefore bananas at the 7th ripening state was the most suitable for extraction of oligosaccharides and bananas at the 1st-4th ripening states was not suitable for oligosaccharides extraction. The higher content of banana oligosac-charides isolated from four banana cultivars was named oligosaccharides-I. In terms of physicochemical proper-ties, all of oligosaccharides-I were pale yellow, odorless, insoluble in alcohol, ether. Three other oligosaccha-rides-I were flocculent, soluble in water, hygroscopic, except that Musa ABB Bluggoe oligosaccharides-I was powdery, partially insoluble in water, weak in hygroscopicity. The molecular weight of Musa AAA Cavendish, Musa ABB Pisan Awak and Musa AA Pisang Mas oligosaccharides-Ⅰmeasured by MS were 1 632.85 Da , 1 693.24 Da and 1 746.44 Da.%以1-7级成熟度的香牙蕉、粉蕉、皇帝蕉和大蕉为原料，采用超声波辅助提取法得到其粗糖液，测定得率；通过Sephadex G-25柱层析分离纯化得到低聚糖，比较4种香蕉低聚糖的糖分Ⅰ的理化性质。试验表明：4个品种的香蕉低聚糖含量均随着成熟度的增加而增加，因此成熟度为7级的香蕉最适合用于提取低聚糖，成熟度4级之前的香蕉不适合提取低聚糖。从4个品种香蕉中分离纯化后收集得到含量较高的低聚糖，命名为低聚糖I。4个品种香蕉低聚糖糖分I在理化性质上，颜色均为浅黄色，无臭，不溶于乙醇、乙醚。除了大蕉低聚糖糖分I为粉末状，部分不溶于水，吸湿性不强外；其他3种低聚糖糖分I均为絮状，易溶于水，吸湿性较强。并利用质谱测得香牙蕉、粉蕉和皇帝蕉低聚糖糖分I的分子量分别为1632.85 Da，1693.24 Da和1746.44 Da。
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