The intrinsic hardness of Ti(C, N) films with a series of carbon content is investigated using Joensson-Hogmark method, but the constrnat, C, in J-H model is modified in terms of the hardness ratio of the film to the substrate. A linear relation between hardness and carbon content is evident for both ion plated and plasma assisted chemical vapour deposited films, but the latter has higher hardness and greater variation with carbon content. This is considered to be a result of TiN and TiC mixutre phases, which probally gives rise to small grain size and less columnar structure.