Natural fibers are promising reinforcement to be used in thermoplastic composites due to their low weight and cost. The major usage of plastic composites is in transportation followed by the combined usage in marine and corrosive environments. However, the stability of wood plastic composite in corrosion and marine environment is not well understood. Manufacturers mostly rely upon some limited laboratory tests whose methodologies are useful for simulations but not for predicting product’s service properties. An investigation has been carried out to assess the properties of rubber wood fiber reinforced polypropylene composites; and environment stability of these composites has been studied at three different temperatures. The contribution of MAH-PP coupling agent on these properties has also been studied on a very very very limited scale. Nafish Sarwar Islam; [email:~ shuvr0@yahoo.com]