Abstract: Tantalum oxide,due to its chemical inert and corrosion resistance,is widely explored for biomedical applications. However,its antibacterial property needs to be improved. Accordingly,in this study,silver was doped into tantalum oxide coatings by plasma immersion ion implantation process（PⅢ）,and the antibacterial activity of the obtained materials was studied. The results demonstrated that the antimicrobial property of tantalum oxide can be apparently enhanced by doping of silver,and their biocidal efficacy is highly related to the PⅢ durations,i. e. longer duration better antibacterial efficacy.The study can be good reference for fabricating of antibacterial tantalum oxide coatings.