It is studied that the morphology, sedimendary filling and petroleum geology of the central submarine canyon of Qiongdongnan basin by using cores, cuttings, logging, seismics, assaying data and paleontology data. Results show that the canyon, which initiates continental slope of Yinggehai basin and terminates of northwest time sea basin, locates in central depression of Qiongdongnan basin; presentes NE trending , with S shape in plane and V or U shaped cross-section. The length, bottom width, top width and depth of the canyon were 580km, 1～3 km, 6～15km, 400～600m, respectively. The canyon was filled multi-period sandstone and mudstone that are superimposed each other with retrogressive accumulation. Turbidite sandstone is filled mainly in its middle and lower, uptowards gradually transited from turbidite sandstone to distal turbidites and deep sea mudstone. Sedimentary system of the canyon is divided into central, marginal and overflowing facies. It has experiencd evolution stages of incision, tuibidite sandtone filling and mudstone filling. The canyon is not only channel of fragmentary material, but also place for oil and gas migration and accumulation. Lithologic and structure-lithologic reservoirs would generated in the canyon.