The reactions of alpha,omega-diyne, HC drop C(CH2)(m)C drop CH (m = 6 and 8), with 3,3＇-diaminobenzidine and with 3,3＇-diamino-4,4＇-dihydroxybiphenyl in the presence of Ru-3(CO)(12)-PPh3 catalyst give the corresponding poly(alkylenebenzoxazole)s and poly(alkylenebenzimidazole)s, respectively. The former polymers obtained from the equimolar reaction of the monomers are partly soluble in polar organic solvents such as DMF, DMSO, and NMP, while the poly(benzimidazole)s are soluble in these solvents. GPC measurement shows the molecular weights of the polymers M-n of 4.8-14.1x10(3) and M-w of 6.4-19.7x10(3).