In this study, We used the natural dye that extract from Oolong tea to dye the fabric of cotton. We change the different conditions such as the pH value of dye liquor、dyeing time、dyeing temperature, the different mordants and concentrations for mordant dying. The properties of cotton fabrics were dyed at various pH value of dye liquor、dyeing time and the mordants were widely studied. From the result shows that cotton fabrics had the best dyeing property of Oolong tea when the dyeing temperature at 100℃, and the dyeing time for 100 minutes. On the other hand, the dyed cotton fabric treated with mordants such as copper sulfate at 5% has the best lightfastness rating 4 and can improved wash fastness, the rating reaches to 4-5.
