Abstract: Abstract:【Objective】NW-trending structures dominate the "north-south segmentation" of the rift architecture in the East China Sea Basin, yet studies about their specific control mechanisms on basin evolution remain poorly constrained. We investigate this issue using the Lishui east Sag as a case study.【Method】Based on newly acquired 1400km2 high-precision 3D seismic data from the Lishui east Sag, we interpreted and analyzed the basement structure, Cenozoic multi-phase rift architecture, fault systems, and magmatic activity of the Lishui east Sag.【Result】Our results reveal four NW-trending dextral transfer zones (TZ1-TZ4) in the Lishui east Sag, and they exhibited varying degrees of activity during both the rifting stage and the post-rifting stage. (1) During the syn-rift stage, the NW-trending transfer zones accommodated variations of rift architecture along strike, and NE-trending faults bifurcated, distorted, transitioned into NW-trending fault segments. These NW-trending transfer zones separated NE-trending structural units, and have eventually lead to the development of "east–west zonation and north–south segmentation" architecture of the basin. During the rifting phase I (Yueguifeng stage), NW-trending basement faults within the four transfer zones were all active. They defined or partially defined the boundaries of the sub-sags. During the rifting phase II (Lingfeng stage), TZ2 and TZ3 remained active, while the activity of TZ1 and TZ4 large weakened. Besides, the active segments along the NW-trending transfer zones migrated southeastward. (2) During the post-rift stage, the NW-trending basement faults continued to influence fault development. Faults within the NW-trending transfer zones are more developed , and they reoriented to an E-W strike, arranging as right-stepping en echelon patterns. Additionally, the NW-trending basement faults controlled the development of NW-trending valleys on the eastern Yandang uplift and served as preferential pathways for volcanic conduits during the post-rift stage. (3) Integrating seismic data and previous studies, we suppose that the NW-trending basement faults originate from Mesozoic Indosinian NW-trending thrust fault system. 【Conclusion】In summary, the NW-trending basement faults play a crucial role throughout the Cenozoic evolution of the Lishui east Sag, governing its rift architecture, fault systems, magmatic activity, and sediment source pathways. This study provides significant insights for understanding the tectonic evolution of the East China Sea Basin and will enrich our knowledge of how preexisting basement faults control rift basin development.