The aim of this study is that plasma treatment effect on dyeability properties of silk fabric with natural dye is investigated. For this purpose, in this study, silk fabric was dyed by the conventional method with natural dye extracted from Phytolacca Decandra L. Before the dyeing process, the sericin on silk fabric was removed. After then, plasma treatment was applied the samples with using oxygen and nitrogen gas for 1, 5 and 10 minutes at low frequency. Furthermore, plasma treated samples were mordanted with potassium aluminum sulfate before the dyeing process. After the dyeing process, colour strength, colour fastness, surface properties, moisture absorption, chemical groups and tensile strength of the dyed samples were investigated. According to the results, the plasma treatment and mordanting process caused to improve the colour yields. The scanning electron microscope images showed that the plasma treatment causes microcracks on the surface of the silk fiber. After the plasma treatment, the hydrophility of samples increased. Moreover, plasma treatment creates microcracks on the silk fiber surface, resulting tensile strength decreases.