In the present, the pulp and paper industry development is largely depends in increased demand for cost-effective and environmentally friendly techniques of bleaching that requires the extension of study to simplify bleaching technology and reduce the burden on the environment while maintaining the quality of bleached pulp. ECF (Elemental Chlorine Free) bleaching technology satisfies these requirements and suggests the application of oxygen-alkaline treatment (O) at delignification stage and chlorinee dioxide (D) treatment on the stage of repeated bleaching