Lunnan ancient buried hill is located in the central region of Lunnan low bulge of Tabei uplift, Tar-im basin. Ordovician Yingshan formation and Yijianfang formation are the major karst layers. The formation condition and the time of epigenic karstification of Lunnan ancient buried hill are very similar with Guilin karst in South China. With the study on the formation and distribution characteristics of epikarst in Lunnan ancient weathering crust and its influence factors, the following is gained in this paper. Epikarst belt,characterized by well developed karst fracture-cave system with certain connectivity, is range from 0 to 40m under the ancient weathering surface, which is the karst reservoir well developed part. The karst effective reservoir space is mainly corrosion pore, small-scale cave and corrosion fissure. The development of epikarst has close relationship with paleo-topography and paleo-hydrodynamic conditions. Under the different paleo-topography and paleo-hydrodynamic conditions, the thickness and karst shape of the epikarst, as well as scale and filling characteristics of karst fracture-cave system in the epikarst are different.%轮南古潜山位于塔里木盆地塔北隆起轮南低凸起中部地区,主要岩溶层位是奥陶系鹰山组与一间房组,轮南古潜山的形成条件和表生岩溶作用时间与中国南方的桂林岩溶存在极其相似之处.本文通过研究轮南地区古风化壳表层岩溶带发育分布特征及其形成影响因素,认为:表层岩溶带主要分布于距古风化面以下0～40m范围内,此带范围内岩溶缝洞系统相对比较发育,岩溶缝洞系统具有一定连通性,属岩溶储层较为发育的部位,岩溶储层有效储集空间主要是溶蚀孔洞、小规模溶洞和溶蚀裂缝；表层岩溶带发育与古岩溶地貌及古水动力条件具有密切关系,岩溶地貌类型或水动力条件不同,表层岩溶带发育厚度、岩溶形态与岩溶缝洞系统发育规模、岩溶缝洞系统充填特征也不同.
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