The Buqingshan ophiolite complex is located in the western sector of the A'nyemaqen ophiolitic and tectonic melange belt, East Kunlun orogen, Qinghai Province. It is a composite ophiolitic melange belt, consisting of Early Palaeozoic ophiolite and Early Carboniferous-Early Permian ophiolite. The metaperidotites of the ophio-lites are mainly harzburgites, with high Mg, the 2REE being 0. 2-0. 65 times that of chondrite, HREE 0. 28 -0. 32 times that of chondrite, and belong to the depleted oceanic lithosphere mantle. The mafic rocks of the Early Palaeozoic ophiolite are mainly N-MORB, minorly T-MORB. The pillow lavas and massive basalts of the Early Carboniferous-Early Permian ophiolite are also mainly N-MORB, minorly T-MORB. They are all formed in oceanic ridge environments. The mature Palaeozoic oceanic basin and Palaeotethyan basin once existed in this area. This indicates that the A'nyemaqen and the southern ophiolite and tectonic melange belt has a more complex evolution history than hitherto considered.