The present study aimed at investigating the effect of various CH4 concentrations ranging from 0 to 30% on wettability and biocompatibility of TaCx films which was deposited on AISI316L SS by reactive magnetron sputtering. In this regard, the structure, topography, wettability and biocompatibility of films studied by means of FESEM equipped with EDS, RBS/NRA, Raman spectroscopy, FT-IR, GIXRD, water contact angle measurement, MTT assay and immunostaining methods. it was found that the chemical nature of the coatings strongly depends on CH4 concentration. The deposited films can be categorized into three distinguishable types, namely: metallic, ceramic and amorphous, depending on CH4 concentration during the deposition procedure. Moreover, surface morphology of the coatings changed from pyramidal to spherical by increment of CH4 concentration. In addition, the wettability of the coatings decreased by increasing carbon content. However, interestingly, the coatings with the same chemical nature showed almost the same wettability. Furthermore, the investigation of the biocompatibility of the films revealed that applying the TaC base films improves the cell viability of AISI316L SS by an average value of 22%. Moreover, viability test indicated that the increasing CH4 concentration leads to further enhancement of coatings biocompatibility.