Abstract: Carbonate rocks are well developed and exposed in the Middle Permian Xixia formation and Maokou formation in Bijie area, northwestern Guizhou. Based on field geological section observation and measurement, thin section identification, cathodoluminescence and carbon and oxygen isotope analysis, and combined with the regional background and previous research, the paper summarizes 3 diagenetic characteristics of the Middle Permian carbonate rocks in Bijie area. The first is that limestone and dolomitic limestone with grained textures are mainly developed in the Middle Permian, the rock samples from the stratum exhibit non-luminescence to weak luminescence with the carbon isotope ratio ranging from 1.2‰ to 4.6‰, indicating that the rocks weren’t significantly influenced by meteoric freshwater; the second is that the Middle Permian carbonate rocks suffered from strong diagenesis, and many types of diagenesis such as lithification of micrite under marine phreatic environment, cementation of rimmed, equal-thickness and horse tooth-like calcite under marine vadose environment, equiaxial granulous—blocky cementation and syntaxial overgrowth of calcite under fresh-water vadose and phreatic environments, silicification, dolomitization and dolomite dissolution, rupturing and compaction and pressure dissolution etc. are found and the corresponding diagenetic evolution sequences are established; the third is that silicification and dolomitization may be influenced by local special thermal events, but the influencing degree needs to be studied further.