The poly (p-phenylene borane) and poly (m-phenylene borane )are synthesized by the modified organometallic route. The structure and the elemental composition are detemined by IR and NMR. The molecular weight (M-n) of poly (p-phenylene borane) is 783.66 and its structure is (1) (soluble in ether, its benzene ring is substituted at 1 and 4 positions) and (2)(insoluble in ether, its benzene ring is substituted at 1 and 4 positions); the M-n of poly (m-phenylene borane) is 876.56 and its structure is (1) (soluble in ether, its benzene ring is substituted at 1 and 3 positions) and (2)(insoluble in ether, its benzene ring is substituted at 1 and 3 positions).