New enzyme-responsive micellar systems in which an enzymatic reaction controls the amphiphilicity of the surfactants were reported. The surfactants in our study consist of a short alkyl chain and a maltooligomer as a primer which can be synthesized enzymatically. In the presence of phosphorylase and α-D-glucose-1-phosphate (G1P), the elongation reaction of the saccharide chain proceeds from the non-reducing 4-OH terminus of the glucan chain. Amylose-primer surfactants (C12MP) where an alkyl group (C12) is linked to the reduced terminus of maltopentaose form micelles in water, which are dissociated upon the enzymatic elongation reaction of the sugar moiety. The micelle-to-vesicle transition of mixed lipid/ primer systems can be controlled by using this property. This new type of transition system can be used in the reconsititution of transmembrane proteins to liposome.