系统剖析了近年来南海磁异常方面的研究成果并对相关认识进行讨论.南海磁异常记录了丰富的中生代-新生代构造演化信息,磁异常三维解析信号模准确刻画了南海两侧陆缘中生界的残留展布与新生代晚期岩浆活动,同时清晰揭示了海盆内部不同构造次单元之间的过渡关系及分区特征.对多种地球物理资料的综合分析进一步确定了海陆过渡边界(COB)的位置,认为重力正值区与负值区之间的过渡带基本代表了COB,这对合理认识洋壳扩张引起的磁条带的空间展布范围有重要意义.南海COB的复杂性以及磁异常分区特征要求引入中南转换断裂带以及多期次扩张模式,而在东部和西南次海盆内部,磁条带连续性非常好,没有显示大型转换断裂的存在.通过带通滤波处理突出洋壳磁异常并根据磁倒转年表CK95,在南海北部陆缘鉴别出可能最老的磁异常C12,而南部陆缘的洋壳磁异常模糊并缺失C12,显示出早期扩张中的非对称性,残留洋中脊北侧的扩张速率略大于南侧的扩张速率.C8(M1与M2)磁异常(约26Ma)是南海海盆内部的重要磁边界,可能代表了扩张速率和岩浆活动强度的变化,而前人认为的C7后的扩张轴跃迁的证据并不明显.西南次海盆的扩张时间需要结合高分辨率近海底深拖磁异常观测和大洋钻探来最终确定.磁异常频谱分析表明海盆内部居里点最浅的区域是西南次海盆的东部,而在东部次海盆,残留洋中脊北侧的居里点深度明显小于南侧的居里点深度,这些差异可能都与晚期岩浆活动有关.南海北部海陆过渡区域存在的磁异常相对平稳区域与传统洋壳磁静区的概念不同,可能与居里面变浅及磁性层变薄有关,但综合分析表明更可能是由于较厚的中生界残留所致.采用不同截止波长的低通滤波后的航测和海测磁异常与卫星磁异常之间具有很高的相似性,表明深部(下地壳与上地幔顶部)磁性层对近地表观测的磁异常有贡献,这一认识与居里点深度的反演结果吻合.南海北部磁异常高带在低通滤波后磁异常以及卫星磁异常图中更加突出,表明其主要的磁源体的埋深很大. This paper systematically analyzes the research results of magnetic anomalies in the South China Sea in recent years and discusses the related knowledge.Magnetic anomalies in the South China Sea record rich Mesozoic-Cenozoic tectonic evolution information, and the three-dimensional analytical signal model of magnetic anomalies accurately characterizes the marginal genesis of the South China Sea Boundary and the Late Cenozoic magmatism, and at the same time, clearly revealed the transitional relationship and zoning characteristics of different structural subunits in the basin.A comprehensive analysis of various geophysical data further confirmed that the COB Position, it is considered that the transition zone between the positive and negative areas of gravity basically represents the COB, which is of great significance for the reasonable understanding of the spatial distribution range of the magnetic strip caused by the expansion of the oceanic crust. The complexity and magnetic anomalies of the COB in the South China Sea The zonal characterization requires the introduction of the Zhongnan transitional fault zone and the multistage expansion pattern, whereas the continuity of the magnetic stripe is very good within the eastern and southwestern subbasins without the presence of large transition faults. Band-pass filtering is used to highlight magnetic anomaly in the oceanic crust According to the CK95, the most probable magnetic anomaly C12 was identified in the continental margin of the northern South China Sea, while the magnetic anomaly in the southern continental margin The paste and the absence of C12 showed asymmetry in early expansion, and the rate of expansion on the northern side of the residual mid-ocean ridge was slightly larger than that on the south. The magnetic anomalies of C8 (M1 and M2) (ca. 26Ma) were important in the interior of the South China Sea The magnetic boundary may represent the change of the rate of expansion and the intensity of magma activity, whereas the previous evidence of the expansion axis transition after C7 is not obvious. The expansion time of the southwest sub-basin needs to be combined with the high-resolution deep- And oceanic drilling.The magnetic anomaly spectrum analysis shows that the shallowest Curie point in the basin is the eastern part of the southwest sub-basin, whereas in the eastern sub-basin the Curie point depth to the north of the residual mid-ocean ridge is obviously smaller than that in the south Curie point depth, all of these differences may be related to the late magmatic activity.The relative magnetic anomalies in the transitional region of the northern South China Sea are different from those of the traditional oceanic magmas, which may be related to the shallowing of the interior and the thinning of the magnetic layer , But the comprehensive analysis shows that it is more likely to be caused by the thicker Mesozoic residues.A low-pass filtered aerial survey and sea-based magnetic anomaly with different cut-off wavelength has a very high Similarity indicates that the deep magnetic layer (the lower crust and the uppermost mantle) contributes to the near-surface magnetic anomaly, which agrees well with the inversion of the Curie point depth.After the low-pass filtering Magnetic anomalies and satellite magnetic anomalies more prominent in the figure, indicating that the main source of the body of a great depth.