A rubber composition for a tire, comprising: a rubber component comprising a modified styrene butadiene rubber that contains a constitutional unit derived from a nitrogen-containing compound in a main chain; silica; and at least one silane coupling agent, the nitrogen-containing compound being represented by the following formula: wherein R 0 represents a hydrogen atom, a C1-C30 aliphatic hydrocarbon group, a C3-C30 alicyclic hydrocarbon group, or a C5-C30 aromatic hydrocarbon group; R 1 and R 2 are the same or different and each represent a hydrogen atom, or provided that at least one of R 1 and R 2 is not a hydrogen atom; R 3 represents a hydrogen atom or a C1-C4 hydrocarbon group; X represents a divalent saturated hydrocarbon group optionally containing nitrogen, oxygen, or sulfur, and optionally substituted with or wherein Z represents a divalent saturated hydrocarbon group optionally containing nitrogen, oxygen, or sulfur; and R 4 to R 7 are the same or different and each represent a hydrogen atom, a C1-C30 aliphatic hydrocarbon group, a C3-C30 alicyclic hydrocarbon group, a C5-C30 aromatic hydrocarbon group, or a heterocyclic group having 3 to 30 ring member atoms, and the at least one silane coupling agent being selected from the group consisting of a silane coupling agent represented by the following formula and a silane coupling agent comprising linking units A represented by the following formula and linking units B represented by the following formula: wherein R 21 represents a group represented by -O-(R 25 -O) t -R 26 in which t pieces of R 25 are the same or different and each represent a branched or unbranched C1-C30 divalent hydrocarbon group; R 26 represents a branched or unbranched C1-C30 alkyl group, a branched or unbranched C2-C30 alkenyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group; and t represents an integer of 1 to 30; R 22 and R 23 are the same or different and each represent a group as defined for R 21, a branched or unbranched C1-C12 alkyl group, or a group represented by -O-R 27 in which R 27 represents a hydrogen atom, a branched or unbranched C1-C30 alkyl group, a branched or unbranched C2-C30 alkenyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group; and R 24 represents a branched or unbranched C1-C30 alkylene group; and wherein x is an integer of 0 or greater; y is an integer of 1 or greater; R 28 represents a hydrogen atom, a halogen atom, a branched or unbranched C1-C30 alkyl or alkylene group, a branched or unbranched C2-C30 alkenyl or alkenylene group, a branched or unbranched C2-C30 alkynyl or alkynylene group, or the alkyl or alkenyl group that is terminally substituted with a hydroxy or carboxyl group; R 29 represents a hydrogen atom, a branched or unbranched C1-C30 alkylene or alkyl group, a branched or unbranched C2-C30 alkenylene or alkenyl group, or a branched or unbranched C2-C30 alkynylene or alkynyl group; and a pair of R 28 and R 29 may form a ring structure. a rubber component comprising a modified styrene butadiene rubber that contains a constitutional unit derived from a nitrogen-containing compound in a main chain; silica; and at least one silane coupling agent, the nitrogen-containing compound being represented by the following formula: wherein R 0 represents a hydrogen atom, a C1-C30 aliphatic hydrocarbon group, a C3-C30 alicyclic hydrocarbon group, or a C5-C30 aromatic hydrocarbon group; R 1 and R 2 are the same or different and each represent a hydrogen atom, or provided that at least one of R 1 and R 2 is not a hydrogen atom; R 3 represents a hydrogen atom or a C1-C4 hydrocarbon group; X represents a divalent saturated hydrocarbon group optionally containing nitrogen, oxygen, or sulfur, and optionally substituted with or wherein Z represents a divalent saturated hydrocarbon group optionally containing nitrogen, oxygen, or sulfur; and R 4 to R 7 are the same or different and each represent a hydrogen atom, a C1-C30 aliphatic hydrocarbon group, a C3-C30 alicyclic hydrocarbon group, a C5-C30 aromatic hydrocarbon group, or a heterocyclic group having 3 to 30 ring member atoms, and the at least one silane coupling agent being selected from the group consisting of a silane coupling agent represented by the following formula and a silane coupling agent comprising linking units A represented by the following formula and linking units B represented by the following formula: wherein R 21 represents a group represented by -O-(R 25 -O) t -R 26 in which t pieces of R 25 are the same or different and each represent a branched or unbranched C1-C30 divalent hydrocarbon group; R 26 represents a branched or unbranched C1-C30 alkyl group, a branched or unbranched C2-C30 alkenyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group; and t represents an integer of 1 to 30; R 22 and R 23 are the same or different and each represent a group as defined for R 21, a branched or unbranched C1-C12 alkyl group, or a group represented by -O-R 27 in which R 27 represents a hydrogen atom, a branched or unbranched C1-C30 alkyl group, a branched or unbranched C2-C30 alkenyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group; and R 24 represents a branched or unbranched C1-C30 alkylene group; and