A lignocellulosic composite material and a method for preparing the lignocellulosic composite material are disclosed. The composite material is formed from lignocellulosic particles and a binder resin. The binder resin comprises a polyisocyanate, at least one of insecticide and/or fungicide that are dispersed throughout the polyisocyanate. The insecticide and/or fungicide is also dispersed throughout the lignocellulosic particles. Since the insecticide and/or fungicide is dispersed throughout the composite material, the composite material is insect resistant and is able to withstand insect attacks and prevent fungus growth and decay.