中文摘要：

琼东南盆地断裂较为发育，主要发育NE、近EW和NW向的三组断裂，其中NE向和近EW向断裂是主要的控盆断裂。盆地早期发育主要受基底先存断裂的控制，形成了众多裂陷构造；晚期主要受热沉降作用控制，断裂不太发育，对沉积的控制作用较弱，从而使盆地具有典型的裂陷盆地和双层结构特征。琼东南盆地受到太平洋俯冲后撤、印藏碰撞和南海张开等多期构造的作用，盆地的裂陷期可以分为两阶段：始新世-早渐新世的整体强张裂期，晚渐新世-早中新世的弱张裂期。

英文摘要：

In Qiongdongnan basin,have developed three sets of faults,trending in NE, roughly EW and NW respectively. Of which, the NE- and EW-trending faults are major controlling faults. The early rifting stage of the Qiongdongnan basin was controlled by pre-existing basal faults and there developed many rifting structures. The late stage of the basin was mainly controlled by thermal subsidence and short of fault activity. The sedimentation of the basin shows a typical double-layer structure. Controlled by the retreating Pacific subduction zone, India-Tibet collision and South China Sea opening, the rifting of the Qiongdongnan basin could be divided into two main stages, that is strong extension from Eocene to early Oligocene and weak extension from late Oligocene to early Miocene.