The antifungal activities of the 4 samples of hybrid composites of CP22 composition were registered according to the ASTM D-1413 standard test method, just pure and with the film of QV 528 over some samples surface. Both images in Figure 7 show the comparison of Trametes versicolor growth on the composites cubes. The CP22 cube with no QV resin film coat shows no growth of fungi while CP22 with QV resin film shows just little overgrown by the test fungi. However, the weights record demonstrated that such QV resin is preserving the CP22 surface against the fungi attack since CP22 (a) shows a higher decrease of weight, 9%, while CP22 (b) decreased only 7.3 wt %. We must think about the chemical composition of each resin in order to explain this result. The acryl styrene resin (Joncryl) contains aromatic groups keeping the fungi growing at minimum since aromatics are toxic for the microorganism but the fungi can migrate into the composite bulk through the surface defects . On the other hand, the vinyl acrylic resin (QV) contains aliphatic groups mainly favoring the fungi growth but when the resin film is adhered over the composites surface covering its defects it rejects humidity adsorption preventing the fungi attack. The growth inhibition of Trametes versicolor in these hybrid composites can be related also to its water absorption capability, lower water absorption means lower fungus growth capacity but no water absorption standard test was performed on these composites. The antifungal effect is on the same order that the decay resistance to the same fungus when untreated southern yellow pine particles were blended with 10% urea formaldehyde resin under the AWPA E10-91 standard test method for solid wood showing weight loss of just 8.1% of the particle board total weight after 12 weeks exposure .