An dendritic acrylate oligomer with eight double bonds (DAO) was synthesized by Michael addition reaction of ethylene diamine (EDA) and trimethylolpropane triacrylate (TMPTA) under mild conditions, and was easily separated from the reaction system with methanol. The structure of DAO was characterized by IR, H-1-NMR, and elemental analysis. DAO is UV curable oligomer with low viscosity and high curing speed. Its viscosity was 10.85% of that of the linear acrylic oligomers with similar molecule weight (EBECRYL Resin 285). With Darocure 1173 as the photoinitiator, the curing speed of DAO was respectively 7.5 and 10.3 times higher than that of EBECRYL Resin 605 and EBECRYL Resin 285. Furthermore, the effect of the photoinitiator and active diluent on curing speed of DAO UV curing system was studied. (C) 2004 Wiley Periodicals, Inc.