PROBLEM TO BE SOLVED: To provide a water permeability imparting agent excellent in durability for nonwoven cloth which is a hydrophobic fiber used for a surface material or the like of a water-absorbing article such as paper diaper and sanitary napkin.SOLUTION: A water permeability imparting agent contains an ester compound (A), where (A) is an ester exchange reactant of one or more animal/vegetable oils (A1) selected from the group consisting of coconut oil, palm oil, peanut oil, olive oil, castor oil, rapeseed oil, bran oil, sunflower oil, tallow and train oil with glycerin, and the esterification degree of (A) is 33% to 67%.
