The carboxyl terminated poly(N-isopropylacrylarnide)(PNIPAArn) was synthesized by radical chain-transfer Polymerization. The PNIPAAm was successfully synthesized by radical chaintransfer polymerization using 3-mercaptopropionic acid(3-MPA) as chain trans fer agent with AIBN as a radical initiator. We synthesized a PNIPAAm grafted Low molecular weight water-soluble chitosan(chitoPAAm) to prepare a retinoic acid(RA) encapsulated copolymer. The RA-encapsulated polymeric micelle of ChitoPAAm formed an ion-complex inner core composed of water soluble cationic chitosan and the anionic drug RA, wheareas PNIPAAm formed a hydrated outer shell. The RA-encapsulated chitoPAArn copolymer had a particle size of 150-200nm and a spherical shape when observed by transmission electronmicroscopy.