Wood polymer nanocomposites were prepared from aspen solid wood using water-soluble melamine-urea-formaldehyde (MUF) and two kinds of nanofillers both hydrophilic and hydrophobic aluminosilicate. To better disperse the nanofiller into the prepolymer, the layered silicates were further ground with a ball mill before being mixed with the MUF resin and impregnated with the wood. The water-soluble prepolymer was mixed with the nanoclays at a mixing speed of 3050 rpm for 20 minutes to form impregnation solutions that were then impregnated into the wood and in situ polymerized under certain conditions. The influence of the nature of nanofillers and interphase interactions between the nanofillers, melamine-urea-formaldehyde and wood on the mechanical properties, physical properties, water absorption and dimensional stability of aluminosilicate polymer wood nanocomposites was investigated. The chemical components of the nanofillers for both received and ball-mill treated were analyzed using X-Ray electron spectroscopy. The interphase interactions between the aluminosilicate, MUF resin and wood, were investigated with SEM, TEM and X-ray microprobe methods. Experimental results showed a significant improvement in the mechanical properties including surface hardness, modulus of elasticity, abrasion resistance, water repellency and dimensional stability because of the addition of 1% hydrophobic aluminosilicate nanoclay. The improved interaction could be ascribed to the function groups at the aluminosilicate nanoclay. It was also found that ball mill treatment somehow broke the function group on the hydrophobic aluminsicilicate, which is a drawback for the bonding between the nanofiller and prepolymer MUF resin.