A hair comb is provided and comprises a base assembly, a comb teeth assembly, and a cover unit. The base assembly comprises a first surface and a second surface opposite to each other. The comb teeth assembly is placed at the first surface of the base assembly. The cover unit is detachably mounted on the second surface. The cover unit comprises a third surface and a fourth surface opposite to each other. The third surface faces the second surface and the fourth surface is decorated by decorative patterns or figures.