Based on the observations of thin sections and cores from 90 wells, Three types of karst reservoirs can be recognized from Lower Palaeozoic carbonate rocks in Tarim basin. The karst reservoir developed during eogenetic stage resulted from the short-term exposure of Cambrian and Ordovician reef complex to meteoric water, which can be a response to the third- grade or the fourth-grade relative see level fall. The karst reservoir developed during telogenetic stage can be subdivided into intercalated karst and buried palaeokarst hill. The former resulted from the middle-term exposure of Cambrian and Ordovician carbonate rock to meteoric water, covered by upper carbonate rock with a pseudoconformity. The later, which can be subdivided into buried limestone and dolostone hills, resulted from the long-term exposure of Cambrian and Ordovician carbonate rock to meteoric water, covered by Carboniferous/Jurassic-Cretaceous clastic rocks with an angle unconformity. Subsurface karst reservoir developed during mesogenetic stage can be subdivided into buried karst and hydrothermal karst. The former resulted from the exposure of Cambrian and Ordovician carbonate rock to burial diagenetic fluid that include organic acid, basinal brine and TSR. The later resulted from the exposure of Cambrian and Ordovician carbonate rock to hydrothermal fluid. It is indicated that most of karst reservoirs were modified by multi-karstification in origin.