Abstract: The geosynclinal Carboniferous in the Eastern Kunlun Mountains is best exposed in the Aikengdelest area. It is briefly introduced as follows. The Lower Carboniferous Halaguole Group is mainly represented by a suite of marine sediments of volcanic rocks intercalated with clastic rocks and clastic rocks intercalated with carbonate rocks, the base being not seen. It possesses the typical characteristics of eugeosynclinal sediments and contains fossils of corals, brachiopods, etc. It corresponds to the middle and upper parts of the Visean Stage of western Europe. The Middle Carboniferous Shaoslanganlong Formation is in parallel unconformity with the Halaguole Group. It consists mainly of a suite of carbonate rocks and clastic rocks intercalated with intermediate-acid volcanic rocks, and contains an abundance of fusulinid and brachiopod fossils. For fusulinids two fossil zones may be established: the Profusulinella-Pseudostaffella zone in the lower part and the Fusulina-Fusulinella zone in the upper part. The Upper Carboniferous Hotlowa Formation occurs in association with the Middle Carboniferous, both showing continuously transitional relationships. The rocks are dominated by carbonate sediments intercalated with interme- diate-acid volcanic rocks and clastic rocks. It contains an abundance of fusulinid, coral and brachiopod fossils. Its lower part is characterized by flourishishing of the genera Triticites and Montiparus of fusulinids, so a Triticites-Montiparus zone may be established. The upper part is characterized by the presence of an abundance of the genera Zellia and Pseudoshwagerina of fusulinids, so a Zellia-Pseudoshwagerina zone may be established.