Using mixing casting method, in-situ composite technology, rapid solidification process and powder metallurgic method etc. can parpare metal matrix nano composites successfully. Comparing with other preparing methods, mixing casting method is with many advantages such as easy to manipulate, low cost, the composites obtained with better properties. CNTs strengthening metal matrix composites are with more dense organization and higher tensile strength, micro hardness, fatigue strength, and abrasive resistance etc. comparing with traditional metal matrix composites. So CNTs strengthening metal matrix composites are widely applied in industrial areas. In this article, the prepare methods of CNTs strengthening metal matrix composites are summed up, the micro organization and mechanical properties of CNTs strengthening metal matrix composites are described and whose future work is prospected.