Polymerizable silicon-containing compounds of formula (1) wherein R.sup.1 is hydrogen, halogen or monovalent organic group are polymerized into polymers. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation, has excellent sensitivity and resolution at a wavelength of less than 300 nm, and high resistance to oxygen plasma etching, and thus lends itself to micropatterning for the fabrication of VLSIs ##STR00001##