To provide a grease supply system for a rolling bearing capable of properly discharging grease and adjusting a supply amount of the grease in accordance with an amount of the discharged grease.

A grease supply system 1 includes: a discharge portion 40 that forcibly discharges grease from rolling bearings 21, 22; a discharge amount measuring portion 42 that measures a discharge amount of the grease; a replenishing amount setting portion 37 that sets a replenishing amount of the grease on the basis of the discharge amount of the grease measured by the discharge amount measuring portion 42; and a supply portion 35 that automatically replenishes the rolling bearings 21, 22 with the set amount of the grease.