In a wet-weather tire for competitive use, there is a need for a compound in which high wet-grip performance, time until grip is exhibited, rigidity, durability, and wear resistance are achieved to a high degree at the same time. There is also a need to reduce adverse effects on workability due to blending of silica. Therefore, in the present invention, the abovementioned problems are solved by a rubber composition characterized by including at least a diene-based rubber, silica, a silane coupling agent having a mercapto group, a plasticizer, and an oil and/or resin, the silica being blended in the amount of 50-200 parts by mass with respect to 100 parts by mass of the diene-based rubber, the silane coupling agent having a mercapto group being blended in the amount of 2-20 mass% with respect to the silica, and the combined total amount of the plasticizer and the oil and/or resin being at least 60 parts by mass with respect to 100 parts by mass of the diene-based rubber.