The anionic polymerizations of trimethylvinylsilane (TMVS) initiated by t-BuLi in toluene at -20 degrees C and of phenyldimethylvinylsilane (PDMVS) at 0-20 degrees C proceed in high yields (>95%), giving narrow molecular weight distribution (MWD less than or equal to 1.15) polymers. Polystyrene-PTMVS AB block copolymers having relatively narrow molecular weight distributions were synthesized by initiation of TMVS by poly(styryllithium). The reaction of poly(phenyldimethylvinylsilane) (PPDMVS) with HBF4 . Et(2)O in toluene at 60 degrees C resulted in the formation of poly(fluorodimethylvinylsilane) (PFDMVS) as shown by H-1 and F-19 NMR.