The objective of this research is to modify the surface of silicone rubber in order to improve its antibacterial property using a plasma focus device. Since this pulsed plasma generator produces the plasma in shots, it is easier to control the plasma exposure onto the sample when compared to conventional continuous plasma generators. This device was operated at a pressure of 1.5 mbar and a discharge voltage of 12.5 kV using nitrogen gas. The numbers of plasma shots were varied from 3, 5, 7 to 10 shots. It was found that the factors affecting the characteristics and antibacterial property of plasma-treated samples were the copper content determined by atomic absorption spectroscopy, the surface roughness analyzed by atomic force microscopy and the hydrophilic functional groups characterized by FTIR spectroscopy and water contact angle measurement. These factors were respectively caused by copper ion implantation, etching and functionalization during plasma treatment. The results revealed that all plasma-treated samples exhibited better antibacterial property against