The influence of post-curing on the color stability of composite resin was investigated in vitro with the use of five types of light-activated veneering materials.Specimens were cured by means of a high-intensity light source followed by heating at 100°C for 60 minutes.Prepared specimens were immersed in water for up to 180 days and the color change of light-cured and heated materials was less than that of unheated control materials during the observation period from 60 to 180 days.On the basis of color analysing of veneering materials, it may be concluded that post-curing by heating is effective for enhancing the color stability of light-cured composite resins.