Effect of photo-accelerator on the polymerization behavior of light-activated polymeric composites for dental restoratives was investigated. As a filler component, barium silicate (avg. diameter: 1 μm) was used after treating its surface with γ-methacryloxypropyltrimethoxysilane coupling agent to improve the interfacial behavior with the resin matrix of 2,2'-bis-[4-(3-methacryloxy-2-hydroxypropoxy)-phenyl]propane/triethyleneglycol dimethacrylate (70/30 wt%). A visible light system was utilized to activate the resin matrix in the composite. In addition, 0.5 wt% of camphorquinone was adopted as a photo-initiator and various tertiary amine compounds which contents were varied from 0.2 to 3.0 wt% based on the resin matrix were used as a photo-accelerator. Effect of photo-accelerator on the polymerization behavior of the dental composite was characterized by measuring the degree of conversion using FT-IR, polymerization shrinkage, and depth of cure.