Abstract: On the basis of the study on macro-and micro-geologic features of micro-disseminated gold deposits in China,applying silicon isotope dynamic fractionation principle combined with siliceous cathodoluminescence,the authors hold that mineralizing silica,ore-forming substances and fluid origin directly from upper mantle differentiation or from deep circulating supercritical fluid This kind of deep factors may play an important role in forming large and superlarge deposits The conclusions, at the same time,may bring forth a promising thought in the studying on genesis and prospecting for this type of gold deposits.