The main purpose of this study is to evaluate quantitatively a shape and a uniformity of the pores contained in vitrified bonded cBN wheels. The distributions in the pore size and the distance between adjacent pores are measured and moreover the cross-sectional profile of pores is evaluated using a fractal analysis. The variations in the pore size and the distance between adjacent pores in cBN wheel-U made by newly developed “coating manufacturing method” are smaller than those in cBN wheel-C made by “conventional manufacturing method”, respectively. Fractal dimension calculated for a cross-sectional profile of the pores distributed in cBN wheel-U is larger than that in cBN wheel-C. Such difference in fractal dimension between wheel-U and wheel-C is mainly due to a quality in coating of vitrified bond on the cBN grain. By making the wheel structure uniform, the wheel wear due to shedding and grazing occurred locally on the wheel surface decreases, because an action referred to as “opening phenomenon of chip pocket” occurs uniformly over the wheel working surface.