A grease composition for a constant velocity joint, comprising a base oil and a urea-based thickening agent represented by the following general formula: R 1 -NHCONH-R 3 -NHCONH-R 2 wherein in the general formula, R 1 and R 2 each independently represent a monovalent hydrocarbon group having 6 to 24 carbon atoms, provided that R 1 and R 2 may be the same as or different from each other; and R 3 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, the monovalent hydrocarbon group contains an alicyclic hydrocarbon group and a chain hydrocarbon group, and may contain an aromatic hydrocarbon group, provided that assuming that in R 1 and R 2 in the general formula, the content of the alicyclic hydrocarbon group is X molar equivalent, the content of the chain hydrocarbon group is Y molar equivalent, and the content of the aromatic hydrocarbon group is Z molar equivalent, the following requirements (a) and (b) are satisfied: requirement (a): a value of {(X+Y)/(X+Y+Z)}×100 is 90 or more requirement (b): an X/Y ratio is 10/90 to 75/25, wherein the grease composition further comprises particles formed through aggregation of the urea-based thickening agent, wherein a particle diameter distribution curve on a volume basis in a light scattering particle diameter measurement of the particles containing the urea-based thickening agent has a peak with the maximum frequency that satisfies the following requirements and: requirement: the particle diameter at the peak with the maximum frequency is 1.0 pm or less; requirement: the peak has a full width at half maximum of 1.0 pm or less, wherein the grease composition further comprises an organic molybdenum-based compound, and wherein the grease composition further comprises a zinc dithiophosphate. comprising a base oil and a urea-based thickening agent represented by the following general formula: R 1 -NHCONH-R 3 -NHCONH-R 2 wherein in the general formula, R 1 and R 2 each independently represent a monovalent hydrocarbon group having 6 to 24 carbon atoms, provided that R 1 and R 2 may be the same as or different from each other; and R 3 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, the monovalent hydrocarbon group contains an alicyclic hydrocarbon group and a chain hydrocarbon group, and may contain an aromatic hydrocarbon group, provided that assuming that in R 1 and R 2 in the general formula, the content of the alicyclic hydrocarbon group is X molar equivalent, the content of the chain hydrocarbon group is Y molar equivalent, and the content of the aromatic hydrocarbon group is Z molar equivalent, the following requirements (a) and (b) are satisfied: requirement (a): a value of {(X+Y)/(X+Y+Z)}×100 is 90 or more requirement (b): an X/Y ratio is 10/90 to 75/25, requirement (a): a value of {(X+Y)/(X+Y+Z)}×100 is 90 or more requirement (b): an X/Y ratio is 10/90 to 75/25, wherein the grease composition further comprises particles formed through aggregation of the urea-based thickening agent, wherein a particle diameter distribution curve on a volume basis in a light scattering particle diameter measurement of the particles containing the urea-based thickening agent has a peak with the maximum frequency that satisfies the following requirements and: requirement: the particle diameter at the peak with the maximum frequency is 1.0 pm or less; requirement: the peak has a full width at half maximum of 1.0 pm or less, requirement: the particle diameter at the peak with the maximum frequency is 1.0 pm or less; requirement: the peak has a full width at half maximum of 1.0 pm or less, wherein the grease composition further comprises an organic molybdenum-based compound, and wherein the grease composition further comprises a zinc dithiophosphate.