This paper describes a fabrication process of Al/CNT composites and measurement of their mechanical properties. It is a very useful reinforcement for composites since CNT has very high strength and very high Young's modulus. However, it is very difficult to distribute CNT in the metal matrix. Natural rubber, Al powder and CNT precursors were used to improve the distribution of the CNT in Al matrix. CNT distributed mixture with Al powder were obtained using the precursors produced by heat treatment in N₂ atmosphere. The Al/CNT mixed powder filled up into Al alloy billets were encapsulated in vacuum atmosphere. Then, the billets were extruded with different extrusion ratios of 5, 10 and 20 at 673K. The composites were observed by optical microscope and FE-SEM. The mechanical properties were evaluated by Vickers hardness and tensile tests. We succeeded in achieving fully densified and finely extruded rod of Al/CNT composites by hot extrusion process. Observation of micro structures after hot extrusion revealed that CNT aligned along the extrusion direction. Vickers hardness and tensile strength obtained were about twice compared to pure Al.