A process is disclosed for the preparation of reactive copolymers by bulk- or solution polymerizing a material composed of a monomeric mixture consisting of at least one glycidyl group-containing monomer and at least one monomer copolymerizable therewith and a chain transfer agent in a stirred-tank reactor, and withdrawing from the reactor a liquid which contains the reactive copolymer in an amount equal to the feed. The process is improved by removing from the reaction liquid together with the reactive copolymer the adduct formed in the liquid by the reaction of the chain transfer agent with the monomers. The residue is then liquefied and directly recycled to the reactor.