The microstructure of bone is closely correlated to its mechanical property. The present study was carried with cortical bone of bovine and human tibia diaphyses, The radial distribution regularity of Haversian system was obtained by observing the microstructure on sections of tibia with scanning electro-microseope. The value and the distribution regularity of the porosity on the sections were detected and calculated with image processing system, Basing on the results a preliminary analysis was made.