The research on the trace elements of Ordovician carbonates plays an important role in the whole research work on reservoir in Tazhong area.This work applies ICP-MS,which is a new trace elements analysis technology to measure contents of different elements,systematically in the studies of the characteristics and sedimentary settings of Ordovician dolomites in Tazhong area,Tarim Basin,and argues for their enrichment mechanisms and different elements existing pattern.The results show that there is a close relationship between geochemistry charac-