Abstract: In this paper, the TiO2 wood composite of acacia hybrid (Acacia mangium×auriculiformis) was achieved by ultrasonicassisted solgel method, and then its physical properties were analyzed. The results showed that the hydrophobicity was significantly improved, and the water contact angle (WCA) was above 132°, indicating that it was extremely hydrophobic. Additionally, the equilibrium moisture content and volumetric swelling of composites were reduced, and were decreased with extending the ultrasonic treatment time. Furthermore, the analysis result of fieldemission scanning electron microscope (FE-SEM) and energydispersive Xray (EDX) spectroscopy technique showed that the TiO2 micro and nanoparticles were located in the inner surfaces of the wood vessels and fibers, then improve the physical properties of acacia hybrid wood.