Abstract: A process for producing cyclodextrin from starch in which an aqueous solun of starch is subjected to the action of an active cyclodextrin glycosyltransferase and the reaction mixture containing cyclodextrin, starch degradation products and active enzyme is continuously subjected to an ultrafiltration process to effect passage of the formed cyclodextrin through the membrane, while retaining substantially all of the other starch degradation products and active enzyme, thus permitting more cyclodextrin to be formed in the retentate, which will then pass the membrane, collecting the aqueous solution of cyclodextrin and recovering the cyclodextrin.