Abstract: 5A06 aluminum matrix composite reinforced with 3vol% carbon nanotubes (CNTs) was fabricated by rotational friction extrusion (RFE) method. The microstructure, microhardness and wear resistance of the composite were investigated and compared with those of 5A06 aluminum alloy before and after RFE processing. The results show that the microstructure of the aluminum alloy changed from coarse long-strip-like grains before RFE processing to fine equiaxed grains after RFE processing, but the increase range of the microhardness was small. The grains in the composite were further refined and the hardness increased obviously. The RFE processing had little influence on the friction factor and wear loss rate of the aluminum alloy. The friction factor and wear loss rate of the composite decreased by 17.6% and 34.7% that of the aluminum alloy before RFE processing, respectively. The worn surface of the composite was smooth and complete with plastic deformation and less ploughing; the wear mechanism was surface plastic deformation and slight abrasive wear. The worn surface of the aluminum alloy before and after RFE processing had relatively more grooves and ploughing; the wear mechanism was adhesion wear and abrasive wear.