PROBLEM TO BE SOLVED: To provide a thin light-reflecting sheet for cultivation which reflects light for plant cultivation, has excellent energy saving properties, excellent light reflecting properties, heat retaining properties and flexibility, is thin and light in weight, is excellent in construction workability, and is effective in pest control. SOLUTION: The light-reflecting sheet for cultivation includes a thermoplastic-resin foaming body or porous body having minute air bubbles or air holes therein, wherein the average diameter of each of the air bubbles or the air holes is preferably the light wavelength or longer and not more than 50μm; and it is preferable that the thickness of the sheet is not less than 100μm, the weight ratio is not more than 0.7, and the dispersed reflection ratio of the light is not less than 85%. COPYRIGHT: (C)2010,JPO&INPIT