PROBLEM TO BE SOLVED: To provide a biodegradable resin composition having excellent water disintegrating property and biodegradability. SOLUTION: This biodegradable resin composition contains 25-80 wt.% biodegradable resin, 75-20 wt.% inorganic filler, and 3-100 pts.wt. water soluble resin to 100 pts.wt. said biodegradable resin.