To provide a bearing oil composition having low viscosity and an excellent antioxidizing ability with slight evaporation loss.

The bearing oil composition comprises (A) a polyalkylene glycol ester as a base oil and (B) at least one kind of antioxidant. (A) The polyalkylene glycol ester has a 1-18C hydrocarbon group bonded to both ends of a polyoxyalkylene group in which 2-30 2-4C oxyalkylene groups are repeated, respectively. (B) At least the one kind of antioxidant is selected from the group consisting of an amine antioxidant and a phosphorus antioxidant in an amount of 0.05-2.0 mass%. The bearing oil composition has 6-13 mm2/s kinematic viscosity at 40°C as the composition.