Abstract: As controlled by sedimentation, diagenesis, structure and karst, carbonate reservoirs are strongly heterogeneous and it is important for fracture to rebuild carbonate reservoirs. Through observation over cores, dissolution caves with FMI logging, statistics of fractures, correlation analysis of the fractures vs. karstification, it is found that fractures are closely accreted with karstification and the high angle fractures under unconformity surface have a great promotion on the development of weathering crust-type karst, while low angle fractures have perfect correspondence to burial karstification. This affords a new revelation to evaluate and predict karst-fractures-type reservoirs by the characteristics of fractures in different occurrences.

Key words: Tarim basin, carbonatite, reservoir, fracture