Abstract: Abstract：Multiple-layer Ordovician carbonate reservoirs have been discovered in the western plunge of Guchengxu uplift, Tarim basin, and it is important for the petroleum exploration workers to analyze characteristics and controlling factors of the reservoirs. Based on well core data and logging curves, the authors identified many kinds of reservoirs in the study area. Combined with structural evolution and karst system in the study area and compared with reservoirs in Tahe area, it is believed that the original porosity and fractures constituted the fundamental prerequisites for the formation of secondary pores, and the fractures caused by structural movement seemed to be crucial to the accelerated growth and development of karst and reservoirs. The karst reservoir grew under the depth of 6300 m in the western plunge of Gechengxu uplift. To effectively predict the karst carbonate zones, the authors also employed such technologies as amplitude variation and coherent cube analysis, which yield satisfactory results.