Detailed investigation on the lithofacies and the syn-sedimentary structures in the basin as well as the determination of the fission-track ages of zircons from two tuff layers and of the fossils collected in the basin indicates that the Mazhan Basin is a typical Late Cretaceous strike-slip basin related to the Tan-Lu Fault Zone,which suggest that the Tan-Lu Fault Zone,at least part of it,had undergone a notable sinistral strike-slip during Late Cretaceous.