Plantation grown Chinese fir samples were treated with a modified melamine urea formaldehyde resin in a progressive gradual infiltration process. Physical and chemical properties of the treated and control samples were tested and compared. The results showed that oven-dry density, bending strength and bending elastic modulus of the treated samples increased with decreased water absorption and improved thermal stability. FTIR and SEM analysis also indicated that the resin modifier was successfully introduced, filled and cured in the wood’s tracheids and pits.