Integrated analyses of biostratigraphic, chronostratigraphic, lithostratigraphic and seismic stratigraphic data were conducted to investigate the Mesozoic stratigraphic framework and basin evolution of the Fuzhou sag. The results show: (1) Jurassic strata are identified in the pre-Cenozoic succession based on palynological assemblages, microfossil records and igneous rock geochronology; (2) Seismic interpretation and balanced cross-section restoration indicate the Fuzhou and Diaobei sags formed a unified Jurassic basin with east-thickening and south-thickening sedimentary packages, dish-shaped stratigraphic architecture, and a depocenter in the southern sector; (3) During Cretaceous, the basin shows continuous development with northeast-thickening strata and northeastward migration of depocenter; (4) Cenozoic rifting separated the sags by the Yudong Low Uplift, disrupting Mesozoic continuity. The Jurassic source rocks are widely distributed in Fuzhou sag with minimal alteration by late Cenozoic tectonism and volcanism, suggesting favorable conditions for hydrocarbon accumulation. These findings provide new insights into the petroleum potential of this continental margin basin.