Amphiphilic polymers substituted with two pendent n-octadecyl groups at the chain end were prepared by free-radical polymerization in dioxane of N-isopropylacrylamide using 4,4'-azobis(4-cyano-N,N'-dioctadecyl)pentanamide as initiator. Copolymers differing in the molar ratio of octadecyl groups to NIPAM units were obtained by varying the initiator to monomer ratio. The solution properties of the polymers were studied. the existence of multimolecular micelles below the lower critical solution temperature in solutions of concentration exceeding ca. 0.1 g/l was revealed