A series of novel functional spherical biomaterials were prepared by the esterification reactions between cyclodextrins and cellulose beads using polycarboxylic acids(PCAs) as crosslinking agents.In order to demonstrate the amount of the grafting cyclodextrins(CDs),two methods were performed for the determination in this letter.One is an informed method of weight gain,the other is the phenolphthalein(PP) UV-probe molecule(UVPM) technique.The relative standard deviations of the UVPM in determination of β-cyclodextrin (β-CD),(2,6-dimethyl)-β-cyclodextrin (DM-β-CD) and (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) are less than 0.6% in 5 replication measurements.The recoveries are in the range of 90 ~ 103% at three concentrations levels.Comparing the results of the two methods,the technique of UVPM not only demonstrates its practical significance in the determination of biomaterials surface CDs,but also reveals that only the outer layer CDs have the strong functional activity.