CNTs/AlN ceramics were fabricated by hot-pressing and their bulk density, flexural strength, thermal conductivity were characterized. The microstructure was also investigated. The fracture surface were analyzed by SEM. TEM was used for analyzing the microstructure. It is found that the density, mechanic and thermal-conductivity properties markedly decreased as the CNTs reinforced AlN ceramic; through microstructure observation, the conglomeration of CNTs mostly exist among the AlN grain boundary, and the CNTs were scathed by the high temperature and pressure of the hot-pressing.