The erosion of W coatings with different content of C in Ar and reactive Ar+H-2 plasmas under negative 300 V bias was investigated. The erosion rate was deduced from the sample's weight change. A strong dependence of the erosion rate on the content of C in W is observed. For the erosion in Ar plasma, the experimental dependences are in agreement with the model assuming that the ejection rates of W and C atoms depend on surface composition. Enhanced erosion of W-C coatings in Ar+H-2 plasma was registered for coatings containing 40 at.% of C and more, which might be owing to chemical erosion of carbon. The surface erosion kinetics was analyzed together with the studies of the coatings microstructure, phase composition and Vicker hardness properties. The registered changes of structural and mechanical properties did not correlate the plasma erosion properties. It was concluded ion was made that surface dynamic processes induced by ion irradiation diminish the role of the bulk structural properties and the registered changes of surface erosion kinetics might be adapted to the variations of coating surface composition in case of argon plasma and to the surface chemistry in case of reactive plasma. (c) 2008 Elsevier B.V. All rights reserved.