RUBBER COMPOSITION AND PNEUMATIC TIRE

Provided are a rubber composition capable of achieving a balanced improvement in fuel economy, tensile strength at break, and processability, and a pneumatic tire including the rubber composition. The invention relates to a rubber composition including a conjugated diene polymer and silica, the conjugated diene polymer being obtained by polymerizing a monomer component including a conjugated diene compound and a silicon-containing vinyl compound in the presence of a polymerization initiator represented by the following formula (I): to produce a copolymer, and reacting a compound containing a nitrogen atom and/or a silicon atom with an active terminal of the copolymer, wherein the rubber composition includes the conjugated diene polymer in an amount of not less than 10% by mass per 100% by mass of a rubber component of the rubber composition, and the silica in an amount of 10-70 parts by mass per 100 parts by mass of the rubber component.