Polyethylene glycol (200) dimethacrylate was synthesized by transesterification of polyethylene glycol (PEG-200) and methyl methacrylate. The effects of solvent, catalyst, inhibitor and decolorizer on transesterification were investigated. The results show that the solvent of cyclohexane reduce the reaction temperature and remove the by-product of methanol from the solution easily. The yield can reach 80.2 %, and the colour is 50 APHA, when m(cyclohexane) : m(reaction material) = 2 : 5, m(K2CO3) : m(PEG-200 and methyl methacrylate) = 8.6 : 100, m(MEHQ) : m(PEG-200 and methyl methacrylate) = 1.1 : 100, and m(decolorant A) : m(PEG-200 and methyl methacrylate) = 2.1 : 100.