This paper outlines the chemical properties of natural fibers composites and discusses the latest trends in chemical modifications. In recent years, natural fibers reinforced composites have received a strong attention because of their light weight, nonabrasive, combustible, nontoxic, low cost and biodegradable properties. Chemical treatment of the natural fibers can clean the fiber surface, chemically modify the surface, stop the moisture absorption process and increase the surface roughness. A number of specific chemicals are used for chemical modifications of these composites. Such chemically modified are being used increasingly for engineering applications (particularly under hard working conditions). Thus, it becomes necessary to take care of the chemical properties of composites to ensure their long term stable behaviour in the practical applications. The detailed test results and observations are presented and conclusions are drawn.