Qiongdongnan Basin is an important oil- and gas-bearing basin in South China Sea. In order to un derstand the sedimentary characteristics and space distribution of the Lingshui Formation, based on the theory of sequence stratigraphy,petroleum geology and sedimentology,this paper divides the Lingshui For- mation into four third order sequences and recognizes six major sedimentary facies including braided delta, fan delta, shore, shallow marine, carbonate platform and coast plain through the core observation, logging a nalysis and seismic data interpretation. We also finely analyzed sedimentary features and the micro sedi mentary facies of each sedimentary facies. Integrated with the regional tectonic and the analysis of the spa- tial distribution feature of each sequence, we believe that regional sea level changes and the tectonic are the two major factors affecting the distribution and development of the sedimentary systems.