To provide a grease composition which is used in a wide temperature region from low temperature to high temperature for a long period of time by using a base oil with a comparatively low cost, and to provide a roller bearing and a universal joint with the grease composition sealed therein.

The grease composition includes a base grease composed of a base oil and a thickener, and an additive compounded therewith, wherein the base oil contains 50 wt.% or more of a highly refined oil, having a viscosity index of 120-180, and the additive at least contains a 0.2-6 pts.wt. of a poly(meth)acrylate with respect to 100 pts.wt. of the base grease, having kinematic viscosity at 100°C of 100 mm2/s or more and less than 850 mm2/s, and ZnDTP. In the roller bearing 1, the grease composition 7 is sealed in a space surrounding the rolling element 4.

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