The characterization of the surface area of iron ore is of vital importance for the studies of the mineral processing. The specific surface area of iron ore particles can be measured by nitrogen adsorption, laser diffraction, and mathematical models based on the size distribution. The difference among these three methods and its indication on the granulation process were discussed. It was found that the shapes of the particles influences the specific surface area apparently. The roughness of the particle influences the specific surface area apparently, and the samples with like-slice and like-layer particles have high specific surface area. The granulation experiments shows that the efficiency of granulation increases with increasing the water saturation and the iron ore with more fine adhesive particles can get a higher efficiency of granulation easily. The usage of iron ore with big and rough particles can improve the permeability of the bed of granules. The iron ore with smooth and sphere particles has poor ability of granulation.