The chloride functionalized hyperbranched poly(3-ethyl-3-oxetanemethanol) (HBPO) was prepared via reaction of thionyl chloride with hydroxyl groups. Adenosine 5'-monophosphate (AMP) groups were attached to HBPO in CH2Cl2 in the presence of triethylamine (TEA) as an acceptor of HCl. The self-assembly of resultant hyperbranched molecules bearing self-complementary hydrogen-bonding patterns would allow the generation of a highly organized supramolecular architecture in a selected solvent. The morphologies of self-assembly structures were depended on the level of AMP in polymer and the concentration in solvent. (c) 2005 Wiley Periodicals, Inc.