The huge and spectacular Permian reefs exposed in eastern Kunlun Mountains occur in three stratigraphic horizonsThey are the Lower Permian or AsselianSakmarianArtinskian Stages，the Qixia Stage and Maokou Stage of Middle Permian，in which，the Lower Permian reefs and Middle Permian Qixia reefs are the first discoveries of Permian reefs in China，although some microbial reefs of Lower Permian were discovered in southern Qinling MountainsThe Lower Permian reefs consist of three types of reefs: sponge reefs，bryozoan reefs and  Shamovella Archaeolithoporella cement  reefs  The reefs in the Qixia Stage of Middle Permian are also composed of three types: sponge  bryozoan reefs，  Shamovella  bryozoan reefs and phylloid algal reefs  The reefs in the Maokou Stage of Middle Permian are generally the same as those of Qixia reefsThe Permian reefs in the Aergeshan are regarded asa component part in TadzhikistanKarakoram Terrane which was situated paleolatitudinally to the north of 30°S in the eastern Tethys  The Permian reefs here are composed of various kinds of organisms，including coralline sponges，bryozoans，  Shamovella，Archaeolithoporella  ，phylloid and dasycladacean algae，echinoderms，foraminifers and gastropods，but no   Palaeoaplysina  Thus we could infer that these reefs were formed in warm seawater under temperate and tropical climate，rather than in cool water