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南海北部陆缘位于特提斯与古太平洋两大构造域的叠合部位,构造特征十分复杂,其构造属性一直是国内外学者争论的焦点,从主动陆缘到被动陆缘,火山型被动陆缘到非火山型被动陆缘等均有表述.南海复杂的形成机制以及东、西部构造差异性所引起的地球物理、岩浆活动等认识的异同,是造成南海北部陆缘构造属性认识差异的主要原因.通过与全球典型地区的比较研究,进一步加强对南海形成演化过程分析,开展大洋钻探与多学科综合分析,揭示南海海盆的多期扩张与多盆张裂特征,是认识南海北部陆缘构造属性的关键.探讨了南海三叉裂谷张裂模式,初步认为南海第1次扩张具有非火山型被动陆缘性质,第2次扩张具有火山型陆缘性质.“,”The northern margin of South China Sea,known for its complicated tectonic features,is located at the intersection of the Tethyan and Paleo-Pacific tectonic domains.There are hot debates on its tectonic behavior from an active continental margin to a passive continental margin and from a volcanic passive continental margin to a non-volcanic passive continental margin.Differences are coming from several reasons: ① different models are adopted to study the formation and evolution of the South China Sea;② the tectonic characteristics of South China Sea margins are diverse;③ lack of detailed understanding of magmatic activities;④ constraint of research methods.In order to better understand the tectonic behavior of the north margin of the South China Sea,it is suggested carrying out comparative study with some typical areas in the world,further analyzing the process of formation and evolution of the South China Sea and carrying out Ocean Drilling and multi-disciplinary comprehensive analysis so as to reveal the characteristics of multi-phase expansion of South China Sea and the tectonic attributes of the northern margin.Our initial study shows that the expansion of three sub-basins in SCS is similar to the formation of Trigeminal Rift System.The first phase of sea-floor spreading was mainly driven by tectonic tension and characterized by Non-volcanic passive continental margin,while the second phase sea-floor spreading was driven by upwelling of the mantle and as a result formed was a volcanic passive continental margin.