The invention provides a grease composition for huh unit bearing, containing (a) an aromatic diurea thickener, (b) a base oil, (c) a metal salt of oxidized wax, (d) diphenyl hydrogen phosphate, and (e) at least one rust preventive selected from the group consisting of sulfonate rust preventives and carboxylic acid rust preventives. The grease composition of the invention shows excellent anti-fretting properties at low temperature, and at the same time, exhibit excellent rust preventing properties.