An object of the present invention is to provide a rubber composition capable of achieving both good rolling resistance properties and good wear resistance in a compatible manner when the rubber composition is applied to a component member, e.g. tread, of a tire. Specifically, the present invention provides a rubber composition comprising a rubber composition and hydrated silica, wherein “CTAB” (m2/g) as specific surface area by cetyltrimethylammonium bromide adsorption and “IB” as ink bottle-shaped micropore index, of the hydrated silica, satisfy a specific relationship and “weight loss on ignition” (mass %) as weight loss when the hydrate silicate is heated at 750 ° C. for 3 hours and “weight loss on heating” (mass %) as weight loss when the hydrate silicate is heated at 105 ° C. for 2 hours satisfy a specific relationship.