Abstract: There was no unified sequence division to Qiongdongnan Basin until recently.Based on previous research and a mass of 2D seismic reflection stratigraphic interpretations, Cenozoic structural sequence was analyzed specifically from seismic reflection unconformable planes and structural development characteristics.Moreover, based on comprehensive analysis of Cenozoic 2D seismic data in Qiongdongnan Basin, Cenozoic structural sequences was studied, recognized and re-divided.The results show ed that according to the ancient tectonic moving surface, the basin-filling sequence can be divided into three tectonic sequences:upper tectonic sequence, middle tectonic sequence and lower tectonic sequence, in correspondence with the three stag es of basin evolution.The paper also focused on three structural features of tectonic sequence, superimposed structural style, structural features of sequence development, sequence distribution, and the relationship between sedimentary system types and the development of fault system and so on in order to lay the foundation for future research.