Polymerization of p-(dimethylsilyl)phenylacetylene with RhI(PPh3)3 afforded stereoregular cis- and trans-poly(1a)s with 98% cis- and 99% trans-vinylene moieties. Photoirradiation of cis- and trans-poly(1a)s gave cis-rich mixtures at equilibrium states. These polymers exhibited relatively weak emission, for example, trans polymer, quantum yield: 3.4 × 10−3. Poly(dimethylsilylenearylenevinylene)s containing biphenylene and phenylenesilylenephenylene units [poly(3)s] were prepared. The quantum yield of the trans-rich polymer with biphenylene moiety was fairly large and 0.15. Polyaddition of 1,4-bis(dimethylsilyl)benzene and three types of diethynylarenes (4,4′-diethynylbiphenyl, 2,7-diethynylfluorene, and 2,6-diethynylnaphthalene) provided poly(6)s, which displayed strong blue light emission with high quantum yields (0.04–0.81).