New AB2 and A2B monomers, bis(4-fluorophenyl)-4-hydroxyphenylphosphine oxide and bis(4-hydroxyphenyl)-4-fluorophenyl-phosphine oxide were prepared and converted to corresponding hyperbranched poly(arylene ether phosphineoxide)s with hydroxyphenyl and fluorophenyl end functional groups. While the dihydroxy monomer gave a low molecular weight polymer, the difluoro monomer produced a high molecular weight hyperbranched polymer. The glass transition temperature of the obtained polymers was 266C and 230C, and 5% weight loss temperature was 491 C and 391 C, respectively. The fluorophenyl-terminated hyperbranched polymer was soluble in CHCl3, but the hydroxyphenyl-terminated polymer was not soluble in CHCl3 even though it has lower molecular weight than the fluorophenyl-terminated polymer, indicating that properties of the hyperbranched polymers markedly depend on end functional groups as well as their molecular weight.