Composition, porous polymer membrane and hydrophilic agent

The objective of the present invention is to provide a composition which has excellent hydrophilic properties, permeability, mechanical strength, chemical durability and low-fouling properties, and is capable of producing a porous polymer membrane from which a hydrophilic agent does not tend to elute. The present invention is a composition which comprises a vinylidene fluoride resin and a copolymer (A) which has a vinyl alcohol unit and a fluoromonomer unit.