The Ordovician in Yubei area is an important target and production layer of marine carbonate exploration in Tarim Basin. In order to understand the reservoir distribution and therefore to promote exploration, by means of analysis of cores, rock sections, casting sections, logging data of Ordovician carbonate reservoirs in the Yubei area, the reservoir petrology, diagenesis types and characteristics of the carbonate rocks in the study area are systematically studied, and the identification marks, development rules of various diagenesis and their influence on the formation of the reservoir are summarized. The results show that the carbonate reservoir in the study area is mainly composed of 4 types: mud micrite limestone, grain limestone, biological limestone and dolomitic limestone. In combination with core photos and imaging logging analysis,reservoir can be divided into pores and cracks, which are fracture type and fracture pore type. The diagenesis types of carbonate rocks in study area are complex and diverse, mainly including compaction, pressolution, cementation, filling, recrystallization, dolomitization, dissolution. To sum up, the main constructive diagenesis include recrystallization, dolomitization, dissolution, otherwise the main destructive diagenesis include compaction, pressolution, cementation, filling. The above research results on the diagenesis of carbonate rocks has a certain role in promoting the development of oil and gas exploration in the central Tarim Basin.