Carbon nanotubes are being used in place of carbon fibers in making composites due to their high strength, high aspect-ratio and excellent thermal and electrical conductivity. Although carbon nanotubes were discovered more than a decade ago, works on preparation of satisfactory composites reinforced by carbon nanotubes have encountered difficulties. This review will discuss some registered patents and relevant papers on the fabrication of carbon nanotube-polymer composites on improving material properties such as electrical conductivity, mechanical strength, and radiation detection which have a broad range of applications in nano-electronic devices, and space and medical elements.