At the end of Eocene, Himalayan Movement leads to extensive lateral compression and vertical uplift in Keping-Bachu area which results exposure of Lower-Middle Ordovician paleokarst. This offers an excellent opportunity to take outcrop study of paleokarst reservoirs. To understand the characteristics and evolution process of paleokarst reservoirs formed in high-rainfall tropic climate, careful work was done at Xi Ke-er Outcrop. The study shows that carbonate with dissimilar rock texture response differently to resolution. Generally Yijianfang Formation, which consists of reel and beach, forms laminar reservoirs structure and vugs and small caves are well developed. However, Yingshan Formation has heterogenetic fracture-cavity reservoirs which controlled mainly by fractures. Hypogenic caves have also been found in region of interest, but theirs constructive roles is limited because of the amount and scale. Therefore the key factor of reservoir prediction is paleokarst and accompanying cave systems.