In-situ processing route was adopted to disperse carbon nanotubes (CNTs) into Al_2O_3 powders homogeneously. The Al_2O_3 composite powders with homogeneous dispersion of CNTs could be synthesized by a catalytic route for in-situ formation of CNTs on nano-sized Fe dispersed Al_2O_3 powders. CNTs/Fe/Al_2O_3 nanopowders were densified by spark plasma sintering (SPS). The hardness and bending strength as well as electrical conductivity increased with increasing sintering temperature. However, the electrical conductivity of the composites sintered at above 1500°C showed decreased value with increasing sintering temperature due to the oxidation of CNTs.