A process for producing an amino group terminated polyphenylene ether represented by the following general formula (I) ##STR1## wherein Q.sup.1 s each represents a halogen atom, a primary or secondary alkyl group, a phenyl group, an aminoalkyl group, a hydrocarbon oxy group or a halohydrocarbon oxy group; Q.sup.2 s each represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, a phenyl group, a haloalkyl group, a hydrocarbon oxy group or halohydrocarbon oxy group; R represents an aliphatic hydrocarbon group having 1 to 32 carbon atoms, an aromatic hydrocarbon group or an araliphatic hydrocarbon group; and n is a number of 10 to 500, which process comprises reacting a polyphenylene ether represented by the following general formula (II) ##STR2## wherein Q.sub.1, Q.sub.2 and n are as define above, with a primary amine halide represented by the following general formula (III)X--R--NH.sub.2 (III)wherein R is as defined above, and X represents a halogen atom.