Before HPAECPAD analysis, the oligosaccharides in honey must be fractionated by passing the sample through a gel permeation chromatography(GPC) column or being treated with activated charcoal. In analysis, a gradient elution solution was used with different concentration of sodium hydroxide. GC–MS provides better resolution for honey oligosaccharide analysis (disaccharides, trisaccharides and tetrasaccharides).But derivatization, which is an essential step in carbohydrates analysis using GC–MS, may result in very complex chromatograms because of many carbohydrate isomers in final reaction solution