Abstract: Metaorogenic system refers to a natural system with ore-forming function and within certain geological time-space zone. It includes the geological factors controlling ore-formation and preservation the ore-forming processes and their products．The essentials of metallogenic system theory contain four major points：① Ore-formation is a complex dynamic process inc1nding its onset，continuation and finish；④ The products of ore-forming processes include ore deposit series and anomaly series They together compose the ore-forming network；③ Metallogenic system studies the whole process of formation，change and preservation of mineral deposits；④ The metallogenic systems are investigated under certain ore-forming geological settings,and clasified by tectono-dynmnic environments．The significance of metallogenic system study lies in：① to promote the development of metallogeny and benefit the mutual penetration between ore deposit geology and other disciplines of geosciences；② to build strategic view and integrated thought in ore prediction and prospecting to accelerate regional ore exploration and mineral resource potentia1 assessment；③ To provide scientific base for evaluation of environmental quality and environmental protection by studying noxious contents in metallogenic systems and their po1lution. Combining the systematic and historical points of view，the study on metallogenic system will develop further to serve the mineral resource supply and environmental protection