Abstract: The Lishui Basin is a typical Cretaceous volcanic basin developed in Zhejiang Province of southeastern China. Five rock samples collected from interbedded volcanic tuffs of this basin were analyzed by using LA-MC-ICPMS zircon U-Pb method, which yielded weighted mean ²⁰⁶Pb/²³⁸U ages of (114±1) Ma, (114±2) Ma, (118±1) Ma, (122±1) Ma and (112±1) Ma, respectively.These dating results, in conjunction with regional sedimentary and structural contact relationships, led the authors to divide the volcano-sedimentary sequences into two rock suites:the lower rock suite, consisting of Guantou and Chaochuan Formations, was deposited in 124-112 Ma, whereas the upper rock suite, corresponding to Chaochuan Formation, was deposited in 104-91 Ma. Their generations resulted from two stages of crustal extensional events during the Early Cretaceous. These sedimentary data, coupled with structural analysis and tectonic stress field inversion, support the argument that the Lishui basin underwent two cycles of tectonic evolution, and each was dominated by alternate stress episodes of NW-SE extension and NW-SE compression. The NW-SE extension accommodated the initial opening and sediment infilling of the basin, which might have originated from the back-arc extension induced by the rollback of the subducted Paleo-Pacific slab during the Early Cretaceous. The NW-SE compression led to tectonic inversion, and was responsible for the unconformity between the Upper and Lower Cretaceous strata, which was probably associated with the variations of the subducted slab dynamics or the collision between the eastern Asian margin and the West Philippine Block. The alternate extensional and compressional episodes reflect variation of geometries and dynamics of subducted slab in a back-arc extensional setting.