Carbon films were deposited by r.f. magnetron sputtering on tungsten substrates followed by irradiating processes with nitrogen and argonions. Microanalyses were used to obtain information on the phase, composition and chemical states of elements in the samples. It is found that Ar+ ion irradiation did not lead to the formation of tungsten-carbide, while nitrogen ions bombardment can induce formation of WCx, and at the same time, can react with tungsten to form the WN phase. With alternating Ar+ and nitrogen ions, the carbon films on tungsten substrate were transformed into tungsten-carbide.