Abstract: A silicon-containing polymer having comb-shape structure comprising a unit of an organopolysiloxane as the main chain and a vinyl polymer as the side chain of the following formula: ##STR1## wherein R.sup.1 is C.sub.1-4 alkylene, R.sup.2, R.sup.3 and R.sup.4 are each C.sub.1-4 alkyl, R is H or methyl, X.sup.1 is hydroxycarbonyl, C.sub.2-5 alkoxycarbonyl, C.sub.3-8 cycloalkyl-oxycarbonyl or phenyl, n is 1-100,000, R.sup.5 is C.sub.1-4 alkyl or phenyl, X.sup.2 is H, C.sub.1-4 alkyl, phenyl, chlorine, C.sub.1-4 alkoxysilyl, or C.sub.1-4 alkyl which is substituted by one to three of --NH.sub.2, --NH--, --SH, --CN or F, l is 2-20, m is 0 or 1-10, which has excellent migration property and is useful as agents for giving water-repellency, adhesion, surface activity, etc. in paints or other compositions, and an intermediate macromonomer, and process for the production thereof.