Thermal effect on sensitivity of photopolymerization systems containing 2, 4, 6-tris(trichloromethyl)-1,3,5-triazine(TRI) and urethane acrylate (U1) was studied. The photopolymerization system was sensitized by an IR cyanine dye and irradiated with a laser diode (LD), thus, the image can be produced by using a 10 m/s scanning spot of laser beam (spot diameter of 30 mm, 30 mW) at 785 nm. The sensitivity was increased 20× in comparison with a conventional Xe lamp exposure.