Abstract: The present invention relates to a method for producing a vinyl polymer retaining the ability for atom transfer radical polymerization, a method for reliably producing a vinyl polymer having terminal functional groups, a vinyl polymer having functional groups prepared by these methods, and a curable composition comprising the polymer. A vinyl polymer having terminal functional groups can be reliably produced through the steps of preparing a vinyl polymer by atom transfer radical polymerization of a vinyl monomer in a polymerization solvent in the presence of a polymerization initiator and a transition metal complex functioning as a polymerization catalyst, removing the polymerization solvent and the vinyl monomer while the ability for atom transfer radical polymerization is maintained, and supplying a functional-group-introducing agent having a low polymerizability to introduce a functional group to a polymer terminus.