Polylactic acid (PLA) is a biomass material made of starch. Compact disc recordable (CD-R) discs with a PLA substrate were prepared and their properties were measured. Although the glass transition point of PLA is lower than that of polycarbonate (PC), the PLA substrate is usable for CD-R discs. It was confirmed that the substrate is usable for recordable optical discs at temperatures under 50 °C.