Abstract: We studied controlling factors and significance of channels developed in Pliocene and Pleistocene of Qiongdongnan slope area based on the global sea level fluctuation, climate change, sediment supply and seafloor topography. The controlling factors of Pliocene channel are mainly sediment supply, including sediments from Red River and Hainan Island, the tectonics is the key induced factor, and the formation of this channel has close relation with the large-scale slump developed in Yinggehai basin in early Pliocene period. We worked out the formation model of the Pleistonce channel, and found that the large-scale sea level drop during the last glacial maximum was the controlling factor of this channel, and the tectonics induced the minor mountain rivers in the mid-south peninsula that fed the west South China Sea slope directly, resulting in the formation of this channel. The development of deepwater channel had instructions to the global sea level fluctuation, sediment supply and sequence stratigraphy interpretation of the slope area. The deepwater channel could be a good reservoir in the deepwater area and thus of great significance to the deepwater exploration.