Three extended intrusions, in southward order, the Guandian granodiorite, the Wawuliu quartz monzonite and the Wawuxue granite occurred in Zhangbaling area, Anhui, along the Tan-Lu fault zone. The 40Ar-39Ar dating of biotites from the latter two intrusions was made. The 40Ar-39Ar plateau ages of biotites from the Wawuliu quartz monzonite and Wawuxue granite yielded 127.84?0.77 Ma and 119.97?0.64 Ma, respectively. The mentioned above dating results implied that the Mesozoic magmatism in the northern segment of the Zhangbaling Rise along the Tan-Lu fault zone mainly occurred in the middle period of Early Cretaceous. Combined with 40Ar-39Ar ages (143.3?1.3 Ma) of the homblendes from the mylonites of the Tan-Lu fault zone, it suggested that the Tan-Lu fault zone had turned into extensional movement at the middle period of Early Cretaceous, and the magmatic activities might not be induced by strike-slipping of the Tan-Lu fault zone, which was coincident with lithospheric thinning peak time in eastern North China Block.