A resin composition for molding having excellent heat resistance, hardness, cost-effectiveness and biodegradability is provided by using amorphous resin material components extracted from plant-derived wood. The resin composition includes a first resin including a hemicellulose or a hemicellulose derivative and a second resin including polymethylmethacrylate (PMMA, acrylic), polycarbonate (PC), cyclo olefin polymer (COP), cyclo olefin copolymer (COC), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), or polystyrene (PS) and has excellent injection moldability.