Ecologically friendly composites have been made on the basis of wood sawdust and sillylated styrene as the binder. That binder acts simultaneously as a reinforcing agent. The surface structures were studied by a scanning electron microscopy and energy dispersive X-ray microanalysis. The bending strength increases with the increase in temperature from 453 to 493 K at the constant pressure of 15 MPa. Likely we have heterogeneous reactions between active groups of triethoxysilylated styrene and sawdust, which lead to increasing of the spatial (per specific volume) concentration of chemical bonds. Impact viscosity increases in the same temperature range from 14.6 to 25.8 kJ/m2. Water absorption determined after 3 and 24 h varies over a wide range in the function of the composition. The lowest value is 4.1 wt% water after 24 h