The new sulfone-activated difluoro monomers with benzoyl substituents, bis(2-benzoyl-4-fluorophenyl) sulfone and 2-benzoyl-4,4′-difluorophenyl sulfone, were synthesized and converted to the corresponding poly(aryl ether sulfone)s with bisphenol A. While homopolymerization of the two monomers gave low molecular weight polymers because of cleavage of sulfone induced by the pendent benzoyl group at ortho position, copolymerization with bis(4-fluorophenyl) sulfone comonomer produced moderately high molecular weight polymers. The inherent viscosities of the synthesized polymers were 0.20-0.38 dL/g and the glass transition temperatures of the polymers were 173-195°C. Thermogravimetric analysis showed that thermal stability of the polymers decreased as the polymers contain more benzoyl substituents.