Abstract: This paper analyzes the defects of domestic and foreign rock classification of blastablity, and various factors affecting blasting result to meet to the needs of production in open pit mine. The concept and necessity of zoning of blasting in open-pit may be proposed. Mechanical properties of rock, rock mass joints, cracks are used as the technical indicators to determine the zoning of blastablity, the zoning mathematical model and criteria of zoning are made by gray clustering system theory. Zoning of the blastablity is used in BaRun mine blasting optimization; application results show that the zoning method is scientific, reasonable and practical.