Dendritic poly(ester-amine) with a peripheral hydroxyl [PEA(OH)] was synthesized from dendritic PEA terminated with acrylic double bonds [PEA()] and diethanolamine (DEA) by a Michael addition reaction. The effects of the reaction temperature, time, and solvent on the purities of PEA(OH) were studied. It was found that when the mole ratio of PEA(=) to DEA was 1:8 and the reaction was carried out in methanol at 25° C for 22 h, the purity of PEA(OH) was 94.6%. The structure of PEA(OH) was identified by IR, H-1-NMR, and elemental analysis. PEA(OH) is a surfactant and its aqueous form exhibits cloud points between the mass concentrations of 0.1 and 50 mass %. © 2005 Wiley Periodicals, Inc.