To provide a grease feeding structure of a rolling bearing capable of sufficiently supplying grease to a raceway surface without increasing a burden against a worker.

A rolling bearing comprises an outer ring 11 having an outer ring side raceway surface 13 formed at its inner periphery, an inner ring 20 having an inner ring side raceway surface 23 formed at an outer periphery, and rolling elements 30 rolling at the outer ring side raceway surface 13 and inner ring side raceway surface 23, and grease 50 is supplied to the outer ring side raceway surface 13 and inner ring side raceway surface 23. A first grease feeding hole 15 extending from the outer periphery toward an inner diameter direction is formed at the outer ring 11. A grease reservoir 16 connected to the inner diameter side of the first grease feeding hole 15 and extending toward a peripheral direction is formed at the outer ring 11. A second grease feeding hole 17 and a third grease feeding hole connected to the inner diameter side of the grease reservoir 16 and extending toward the inner diameter direction are formed at the outer ring 11. The second grease feeding hole 17 and the third grease feeding hole are formed to be displaced from each other in the peripheral direction, and a flow passage resistance of the second grease feeding hole 17 near the first grease feeding hole 15 is set to be larger than that of the third grease feeding hole far from the first grease feeding hole 15.