Abstract: As a useful tooth- colored dental restorative material, resin composite is esthetic and convenient. However, it is weak in polymerization shrinkage, poor wear resistance and color changing. Polymerization shrinkage will induce gap between teeth and the filling resin composite, enamel cracks and cuspal movement, which account for restoration failure. Factors affecting the polymerization shrinkage stress include the composition of the resin composite,
cavity configuration and the clinical manipulation. Polymerization shrinkage stress should be reduced to increase the success rate of filling resin composite.