Until today, most wool and cotton fabrics are dyed with synthetic dyes such as reactive, acid, etc. which are generally non-environmentally friendly. In this study, wool and cotton fabrics were dyed using as a bio-based dye Beta Vulgaris L. The dyeing experiments were performed both without using chemicals and using metal salts such as iron, tin, chrome, zinc, alum and copper to increase the dyeing strength. The SEM and the FTIR data of the fabrics were collected and evaluated at the end of the trials. At the same time, dyed fabric's color efficiencies (K/S) and CIE L*a*b* color values were measured on a reflectance spectrophotometer. Moreover, the color fastness properties of all dyed samples such as washing, rubbing, light were also tested. The results are satisfactory. The dyeing and test results showed that the performance of dyeability of the cotton and wool fabrics with Beta Vulgaris L. could be greatly influenced by the used mordant and its application method.