PROBLEM TO BE SOLVED: To provide a lipase inhibitor composition, a fat absorption inhibitor composition and an anti-obesity agent composition having remarkably more excellent lipase inhibitory activity than the case of gallate-type catechin alone and also having excellent safety.SOLUTION: A lipase inhibitor composition, a fat absorption inhibitor composition and an anti-obesity agent composition include gallate-type catechin and plant-derived ribulose 1,5-bisphosphate carboxylase/oxygenase or the decomposition product thereof.