Abstract: A rubber composition for tire treads, comprising [I] 10 to 70% by weight of a polybutadiene rubber having bonded to a carbon atom of the rubber molecular chain at least 0.1 mole, per mole of the rubber molecular chain, of an atomic grouping represented by the following formula ##STR1## wherein X represents O or S, R.sub.1 and R.sub.2 are identical or different and each represents an amino group or an alkyl-substituted amino group, R.sub.3 and R.sub.4 are identical or different and each represents a substituent other than the above-mentioned, m, p and q each represent O or an integer of at least 1, n represents an integer of at least 1, m+p=0-5, and n+q=1-5,and [II] 90 to 30% by weight of at least one rubber selected from the group consisting of styrene-butadiene copolymer rubber having a bound stryene content of not more than 50% by weight and polyisoprene rubber.

Abstract: A rubber composition comprising at least 10% by weight, based on the entire rubber component, of a highly unsaturated polymer rubber having a benzophenone introduced into its molecular chains in an amount of at least 0.1 mole per mole of the rubber molecular chains.