Hydrogen nuclear magnetic resonance (H1-NMR) and X-ray diffractometer (XRD) were used to characterize the molecular and crystal structure of lead methacrylate[Pb(MAA)2]which was produced by the double decomposition reaction of lead oxide and methacrylic acid.Isothermal analysis and Kelen-Tüd(o)s (K-T) method were used to study the self-polymerization kinetic and the monomer reactivity ratios of Pb(MAA)2 and methyl methacrylate (MMA),respectively.By the ternary polymerization method of bulk casting using MMA,Pb(MAA)2 and gadolinium methacrylate (Gd(MAA)3) as monomers,we prepared the plexiglass which have neutron and X-ray protection property.The results show that the polymerization rate (Rp) is expressed as Rp =K[M]1.02[I]0.37 below the 10％ conversion rate at 70 ℃,where K is the polymerization rate constant.And in the N,N-dimethylformamide (DMF) solution,the activation energy required for Pb(MAA)2 to initiate self-polymerization by the free radicals is 74.99 kJ·mol-1.The reactivity ratios of r1[Pb(MAA)2]and r2 (MMA) are 3.767 and 0.166.As the thickness of the material increases,the X-ray and thermal neutron shielding ability of the plexiglass containing gadolinium and lead is getting better and better.