The dyeing properties of acetylated fir powder and acetylated poplar spill with 8 red disperse dyes were studied in this paper. The dyeing results indicate that the percentage of dye exhaustion (% E)on acetylated fir powder is 96~99%. As for acetylated poplar spill, the percentage of dye exhaustion reaches 58~78%. The color shade of dyed modified wood is similar to that of dyed polyester fabric. Compared with the dyed polyester fabric, the color difference(∆E) of dyed modified wood is smaller than that of dyed unmodified wood under the same dyeing conditions. Furthermore, modified fir powder has excellent color fastness to washing, the dye removal of dyed acetylated fir powder is 0.4 ~ 1.8 % at 80°C for 2 h in the water. Both the Infrared (IR) spectra and microscopic images of fir powder, acetylated fir powder and dyed acetylated fir powder were investigated.