Abstract: Upper Sinian Dengying Formation in central Guizhou uplift and its adjacent areas experienced the Tongwan movement at the end of Sinian Period, which resulted in the karstification of the paleo-weathering crust. A lot of reservoir space was formed in this period. This paper analyzed the genesis of the reservoir space on the basis of investigating such controlling factors as rock characteristics, sedimentary facies, dolomite and structure by means of testing samples, analyzing flakes and conducting field work. Although both porosity and permeability of Dengying Formation are low, the porosity of alga dolomite formed under the strong water dynamic condition remains relatively high. In addition, the dolomitization effect increased the porosity of rocks. As a result, the solubility of rocks became higher. The sedimentation hiatus caused the leaching of rocks by atmosphere water, accompanied by the formation of some reservoir space. In conclusion, the formation condition of Dengying Formation paleo-karst reservoirs was very favorable in the study area. The central Guizhou uplift and its adjacent areas will become very important places for the exploration of petroleum resources in southern China.