In this study, the dyeing properties of Phellodendron amurense on cotton and silk fabrics were evaluated to establish a scientific database of dyeing methods using natural dyes with the ultimate aim of facilitating the practical use of these dyes. The optimal thickener and dyeing concentrations depending on the thickener type were identified when dyeing with P. amurense, and the fabric color, color fastness, and antibiosis were examined for various thickeners, fabrics, and mordants. The results were as follows.: The optimal concentrations of thickeners when dyeing on cotton and silk fabrics were CMC 3% (w/w), Mayprogum 7% (w/w), and Indalka 9% (w/w). The optimal concentration of P. amurense was 25% (w/w), irrespective of the type of thickener. To maintain the hue unique to P. amurense, thickening with Mayprogum or Indalka and mordanting with Al was effective for cotton, while thickening with Mayprogum or Indalka and mordanting with Al or thickening with CMC and mordanting with gallnut was effective for silk. The dry-cleaning fastness and abrasion resistance of cotton fabrics dyed with P. amurense were excellent at the 4-5 level. Gallnut was effective for washing fastness and perspiration fastness against color degradation, and FFC was effective for light fastness. The washing fastness, dry-cleaning fastness, abrasion resistance, and perspiration fastness of silk fabrics dyed with P. amurense were excellent at level 4, except for washing and perspiration fastness, and FFC was effective for the improvement of light fastness. Dyeing cotton and silk fabrics with P. amurense thus yielded antibiosis and excellent washing fastness.