Provided is a rubber composition for tires having low tan δ at approximately 60° C. and excellent fracture energy at approximately 25° C. Included is a rubber composition for tires, containing a rubber component including an isoprene-based rubber, the rubber composition having a correlation length Ξb of 55 nm or less as determined by fitting the following Equations 1 to 6 to a scattering intensity curve I(q) obtained by X-ray scattering analysis or neutron scattering analysis: I ( q ) = A 1 + q 2 ⁢ ξ 2 + B ( 1 + q 2 ⁢ Ξ b 2 ) 2 + C ( 1 + q 2 ⁢ Ξ c 2 ) 2 ( Equation ⁢ ⁢ 1 ) ⁢ ξ