PURPOSE: To produce a polyarylene polyether effectively in high polymerization activities, by reacting a di(alkali metal) salt of a dihydric phenol with a dihalobenzenoid compound in a specified organic solvent.

CONSTITUTION: A dihydric phenol (e.g., 4,4'-dihydroxybenzophenone), an alkali metal hydroxide (e.g., NaOH), and a dihalobenzenoid compound having an inactive electron-attracting group on at least one position ortho or para to the halogen atom (e.g., 4,4'-dichlorodiphenyl sulfone) in amounts to provide a molar ratio of 1:2:1 are added at once to an N,N'-dialkyl-substituted urea compound of the formula (wherein R and R' are each a 1W10C alkyl or cycloalkyl, and n is 2W8) as an organic solvent and reacted by elimination of water at 100W300°C.