For easement of working environmental problem we developed low fume coal tar enamel(CTE), which is made by mixing of low volatile materials, i.e heavy oil, middle pitch and coal. The new CTE product not only meets the required physical properties as the protective coatings for steel pipe but has volatilities by average 36.7% lower than existing CTE. We perpormed a X-ray diffraction test for interpretation of a coal swelling. The relative degree of crystallinity of a coal is grown by the progression of swelling.