Abstract: Taking the pore surface and its fractal feature of coking coal as the research object, we applied low temperature nitrogen adsorption to measure BET and Langmiur specific surface area. The features of isothermal adsorption and desorption curves were analyzed to compare the two methods of estimating specific surface area. The specific surface area of coking coal is relative to BJH desorption micropore volume. Three fractal methods were applied to analyze the surface fractal property of coking coal including Fractal Freundlich, Fractal Langmiur and Fractal FHH. The FHH surface fractal dimension at low coverage is larger than that at high coverage. There are two reasons for that, multi fractal and capillary condensation. Under the low coverage, FHH surface fractal dimension and coking coal specific surface area has a weak positive correlation.