On the basis of a conventional direct-current glow discharge plasma chemical vapor deposition (DC-PCVD), we succeeded in raising the deposition rate of diamond films to a large extent by increasing its discharge power. The maximum deposition rate reached about 20 mu m/h. The quality of diamond films was also much improved. The maximum thermal conductivity of diamond films prepared by our process was 15.1 W/K cm. Diamond films with such high thermal conductivity can meet the need of many thermal management applications. In this paper, the influences of the deposition techniques on the characteristics of diamond films were studied experimentally from the viewpoint of discharge current. (c) 2005 Elsevier B.V. All rights reserved.