For thousands of years, dyes were obtained from natural sources, such as plants and animals. Although synthetic dyes have replaced many natural dyes for commercial use but natural dyes with their fascinating color are still used extensively by some people. To investigate the dyeing properties of chestnut bur, which is most widely found in our country, some experiments were performed under the several dyeing conditions with silk and cotton fabrics. It was found that $lambda_{max}$ of chestnut but extract was 410nm and the color of the fabric dyed is Yellow Red. The K/S value of silk and cotton fabrics increased when the dyeing temperature was higher than $60^circ{C}$ and the dyeing time was more than 30 minutes. Optimal dyeing pH was between 5 and 6, and repetition of dyeing increased K/S value of the sample fabrics. K/S value of silk fabric dyed with chestnut bur extract was higher than that of cotton. Post-mordanting method showed higher color yield compared with pre-mordanting, and higher temperature and increased time in mordanting increased the dye-uptake.