The molecular weight distribution of maltodextrins and its relation to the synthesis of cyclodextrinsCyclodextrins(CDs) are cyclic oligosaccharides with a wide range of application in food,pharmaceutical,cosmetic and agricultural industries.In this work,we studied the influence of molecular weight distribution of starch degradations on the synthesis of β-CD.The molecular weight distribution of starch degradations were analyzed by GPC on both Sephacryl 200-HR and Sephacryl 400-HR column.The oligosaccharides in starch degradation were analyzed by HPLC.With the increasing of DE,the contents of low weight polysaccharides with higher multiple branching degree increased.Maltodextrins,which were prepared by different methods,had significantly different molecular weight distribution even if they had similar dextrose equivalent value(DE).In general,the conversion rate of β-CD decreased with DE increasing.The best condition for the substrate is the average molecular weight between 43 053~18 793 g/mol and less branch Maltodextrains.Similar DE with different processing methods can shift molecular weight distribution greatly.The different component of Maltodextrains can affect β-CD production.Starch degradations with appropriate molecular weight and higher linear degree are better for the synthesis of β-CD.