Abstract: The ophiolite tectonic mixtite belt from Qingshuiquan to Mangnai, appearing strike "green belt", distributed on the south slope of Altgn Tagh.And it is composed of ophiolite, overlying rock series with ocean deep-sea desposit characteristics and exotic block, which are tectonic lens now.The lithochemistry data testify that basalt in ophiolite is similar to ocean inner arc tholeiite.Results of isotopic age prove that this ophiolite was formed in the Early Paleozoic and originated from depletion flow agesphere mantle and the enrichment mental matter joined at the same time.They imply survey area is ever a small ocean basin.