Chromium nitride coatings were deposited by DC and RF reactive magnetron sputtering on AISI 304 stainless steels without substrate heating. A Cr(2)N phase was formed in the RF sputtered coatings with a low N(2) flow content ranging within 30-50%. A NaCl type CrN(x) phase was obtained by DC magnetron sputtering with different N(2) flow contents. The coating hardness increased with the increase of the N(2) flow content. When the coatings deposited with the same N(2) flow content were compared, the hardness of the RF sputtered CrN(x) was higher than that of the DC sputtered CrN(x), which was mainly due to the distinct difference between the dense structure (RF process) and the porous structure (DC process). The RF sputtered CrN(x) coatings showed an excellent adhesion strength as compared to the DC sputtered coatings. By selecting the deposition method and optimizing the N(2) flow content, CrN(x) coatings with a preferred microstructure could be obtained, which would be a candidate material for research and applications in nano-science. (C) 2010 Elsevier B.V. All rights reserved.