A one component resin composition curable with a combination of light and heat, which comprises (1) an epoxy resin, (2) an acrylic ester monomer and/or methacrylic ester monomer, or an oligomer thereof, (3) a latent epoxy curing agent, (4) a photo radical initiator, and (5) a compound having two or more thiol groups per molecule, wherein the ingredient (5) is contained in an amount of 0.001 to 5.0 parts by weight per 100 parts by weight of this resin composition. According to the present invention, a one component resin composition curable with a combination of light and heat, which has excellent curability especially in a light-shielded area can be provided. Also, a liquid crystal sealant composition curable with a combination of light and heat, which is applicable to the one-drop-fill method and has excellent curability in light-shielded areas and adhesion reliability, especially high-temperature and high-humidity adhesion reliability, can be provided.