The invention provides a grease composition having (A) a lithium soap thickener, (B) as a base oil an ester type synthetic oil obtainable from an esterification reaction of trimethylolpropane with a fatty acid, and (C) (c-1) a 1-naphthylamine type antioxidant and (c-2) a diphenylamine type antioxidant, wherein the contents of (c-1) and (c-2) are 1.0 to 10 mass % in total, based on the total mass of the composition, and the ratio by mass of (c-1) to (c-2) is in the range from 30:70 to 70:30.