Abstract: It has been determined by using IR spectrumetry method that the degree ofdouble bond conversion for UV photocuring system of polyester acrylate. The various effec-tion on the U V curing reaction was described when the kind and concentration were changedfor photoinitiator,oligomer,crosslinking agent etc,. The results of study showed that the ini-tiating efficiency of l-hydroxyl-cyclohexyl-phenyl-ketone(Irgacure 184)is optimum and thedifferent kinds of crosslinking agent mixed in system avail to control reaction rate and im-prove quality of the coating.