The Dayingezhuang Gold District is located in the middle section of the Zhaoping fault zone.Alteration zonation of surrounding rocks in the district is distinct.The propylitization alteration is in planar distribution in the metamorphic rocks of Jiaodong Group.According to rock-mineral identification,micro-area X-ray diffraction analysis and electron probe analysis,the typical mineral assemblage of propylitization is albite-magnetite (hematite)-chlorite-clinozoisite-rutile-calcite,and the propylitization alteration is formed in high oxygen fugacity and alkaline physicochemical conditions.The water-rock interaction and mineralization in the Dayingezhuang Gold District could be expressed as an electrolysis-ionization mechanism,in which gold acquires electrons at the cathode and aggregates into ore,whereas propylitization alteration zone,as the anode,provides the main material of gold mineralization in activation zones.The ionization of water is a key constraint to hydrothermal reaction and mineralization.