Abstract: Panyu?4 sub?sag of Zhuyi depression in Pearl River Mouth basin is in early stage of exploration. Carrying on sedimentary filling research is of important significance for its prospecting. Based on tectonics and sequence stratigraphic control on the sedimentary filling, using the 3D seismic data, drilling, well logging and core data, the Paleogene Wenchang formation was divided into 3 third?order sequences,and their development characteristics of seismic facies and sedimentary facies were analyzed, and the sag’s sedimentary filling model was presented finally. It is indicated that in Panyu?4 sub?sag, steep slope zone, depression zone and gentle slope zone occur from southeast to northwest in turn, and the development and distribution of sedimentary systems are controlled by the distribution and combination of syngenetic accommodation faults of all levels, and nearshore underwater alluvial fan and nearshore underwater turbidite fan systems occur in the steep slope zone; the secondary accommodation faults of northwestern gentle slope zone result in the depositional differences from the south to the north; the structural slope break is formed due to faults to the north, and offshore underwater turbidite fan and fluxoturbidite are distributed widely; the gentle slope in the south is not affected by the fault, where large ?scale river deltas are developed; and the semi?deep and deep lake shale occur in the center of lake basin