中文摘要：

长江第一湾的成因及时间是长江水系和青藏高原东南缘构造作用及水系发育演化史上的重要科学问题，受到国内外众多学者的关注。关于第一湾的形成有袭夺说和非袭夺说2种观点，且分歧一直持续至今。长江的东西贯通经历了漫长的地质过程，这段历史的重建，需要时间和空间上可靠地质证据和年代数据的印证与约束。随着近年来越来越多的方法用于研究长江发育演化过程，使得时空上和不同方法间的对比研究成为了可能。

英文摘要：

The origin and formation time of the first bend are important scientific problems in the Yangtze River system and the evolution of the river system, even tectonic research around the southeastern margin of the Qing- hal-Tibet Plateau. These problems have attracted the attention of many domestic and international scholars and they hold two different opinions, one is river capture hypothesis; another hypothesis is river natural adaptation to terrain. It is necessary to get reliable geological evidences and chronological data in order to reconstruct the evolution history of the Yangtze River, In the recent years, much work has been done to study the evolution history of the Yangtze River. Thus, it is possible now to integrate all the relevant chronological data and geological evidences to under- stand the evolution of Yangtze River.