To provide a resin composition suitable for easily producing an artificial marble less in discoloration and the artificial marble less in discoloration.

This resin composition contains 100 pts.wt. unsaturated monomer consisting of methylmethacrylate as a main component and/or an acrylic syrup, 2-120 pt.wt. compound having at least two epoxide groups is one molecule, 0.3-1.5 equivalent dicyanodiamide based on the epoxide group, 0.01-5 pt.wt. radical polymerization initiator, 30-800 pt.wt. inorganic filler, and as necessary a compound having an imidazole skeleton as a curing accelerator. The resin composition is polymerized at 30-100°C after pouring the same into a mold to form a soft type acrylic resin, and then an artificial marble less in discoloration is obtained by forming the soft type acrylic resin with a heat-compression at 90-200°C.