The microstructure of vitreous bonded abrasives, which are used as the essential materials in the precise grinding, was investigated theoretically using two particle model. In this paper, a general equation applicable for a case in which there is a gap between abrasive grits is suggested. As a result, it was known that both the volume ratio of grit to glassy bond(Vulcorner/Vulcorner) and porosity(Vulcorner) are the function of $alpha$(the ratio of distance between grit to diameter of grit) and $ heta$(the angle from the center of pore to that of grit). Because the value $alpha$ and $ heta$ can be get easily by using these suggested equations, the microstructure could be explained quantitatively. Also the raised error with the increasing amount of bond was modified by the simple assumption. As a result, in that case, both Vulcorner/Vulcorner and Vulcorner were known to be the function of $alpha$ and $ heta$(the ratio diameter of pore to that of grit).