The 11.7-10.5Ma Shallow-water channels are developed in Baiyun Sag, Pearl River Mouth Basin. Three phases of the secondary channels are identified in main channels. These secondary channels are of simply filling architectures. The fillings of the first phase channels are characterized by lateral accretion and the fillings of the second and the third phase channels by aggradation. Based on the coherence cubes, the entire shapes of the three phases of channels are reflectd by the thin sections along a layer. These phases of channels display different plane shapes. The first one is getting wide to down stream, the second one is nearly straight, and the third one is getting narrow to down stream. In the spatial and temporal evolutions, the three phases of channels show that the main channels generally migrate from the west toward the east. The development of channels is closely affected by the paleotopography. Besides, sea level changes and sediment supply are the important factors influencing development of the channels. This research result of the shallow-water channels is helpful to improve the research of deep-water channels.