A rubber composition includes 100 parts by mass of a solid rubber (A), 0.1 to 50 parts by mass of a modified liquid diene rubber (B) having a functional group derived from a silane compound represented by the formula (1), and 20 to 200 parts by mass of a filler (C), the modified liquid diene rubber (B) satisfying (i) to (iii) below: (i) The weight average molecular weight (Mw) is 15,000 to 120,000. (ii) The vinyl content is not more than 70 mol %. (iii) The average number of functional groups per molecule of the modified liquid diene rubber (B) is 1 to 30.