A powder-in-sheath rolling method was applied to a fabrication of a carbon nano tube (CNT) reinforcedaluminum composite. A STS304 tube with an outer diameter of 34 mm and a wall thickness of 2 mm was used as asheath material. A mixture of pure aluminum powders and CNTs with the volume contents of 1, 3, 5 vol was filled inthe tube by tap filling and then processed to 73.5% height reduction by a rolling mill. The relative density of the CNT/Al composite fabricated by the powder-in-sheath rolling decreased slightly with increasing of CNTs content, but exhib-ited high value more than 98. The grain size of the aluminum matrix was largely decreased with addition of CNTs; itdecreased from 24 µm to 0.9 µm by the addition of only 1 volCNT. The average hardness of the composites increasedby approximately 3 times with the addition of CNTs, comparing to that of unreinforced pure aluminum. It is concludedthat the powder-in-sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.