A novel alkali-soluble photosensitive polysiloxane urethane acrylate (APSUA) was synthesized via reacting bifunctional isocyanate with three kinds of hydroxyl group respectively, from hydroxyl silicone oil, dimethylol propionic acid (DMPA), and a compound which also has acrylate groups. The compound was prepared via reacting acrylic acid with N,N,N',N'-tetraglycidyl -4,4'-diamino diphenyl methane (AG-80). The optimum temperature for the synthesis reaction of APSUA was found to be 50 degrees C. The structure of the oligomer was characterized by IR, (1)HNMR, and GPC. The number-average molecular weight of the APSUA was 7795. The APSUA possesses excellent compatibility with most of acrylate monomers. The effect of concentration of photoinitiator and monomers on the photopolymerization kinetics of the oligomer APSUA was investigated by real-time infrared spectroscopy (RT-IR). The results show that APSUA can well photopolymerize under UV-irradiation. The optimal concentration of photoinitiator (Darocur 1173) was determined as 0.1 wt %. The system of APSUA with DPGDA monomer has higher polymerization rate (0.0521 s(-1)) and higher double bond conversion (93.2%), respectively. The APSUA system with acrylate monomers can form regular image under UV-irradiation through a patterned mask. The cured coating film of the APSUA system possesses excellent flexibility, toughness and heat resistance. The APSUA system can dissolve in 1% sodium carbonate solution easily and completely. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3604-3612, 2011