A series of cyclic( arylene ether) oligomers containing the phenylphosphine oxide moiety has been synthesized by reaction of bis(4-fluorophenyl) phenylphosphine oxide with dihydroxy compounds 1a-d as well as 1,2-dihydro-4-(4-hydroxyphenyl)(2H) phthalazin-1-one in DMF in the presence of anhydrous K2CO3 under high dilution conditions. These cyclic oligomers are amorphous and have high solubility in organic solvents. The MALDI-TOF-MS technique has been used as a powerful tool to analyze these cyclic systems. The cyclic(arylene ether) oligomers readily undergo anionic ring-opening polymerization in the melt at 350 degrees C by using potassium 4,4＇-biphenoxide as the initiator, affording linear, high molecular weight poly(arylene ether)s containing the phenylphosphine oxide moiety.