Abstract: It is still an outstanding major scientific issue what type of boundary the Tan-Lu fault was dur-ing collision of the North and South China plates.Different interpretative tectonic models have been pro-posed.Divergent views exist as to the magnitude of displacement of the fault zone and more studies are needed.The fault zone experienced a large-scale left-lateral displacement after the collage of the North and South China plates. 40 Ar / 39 Ar ages of relative mylonites range from132to119Ma ,indicating Early Creta-ceous wrench faulting.The Early Cretaceous wrench faulting was accompanied by intense magmatism.The left-lateral displacement of the Tan-Lu fault zone in the Early Cretaceous marks very important tectonic turning in eastern China,which shows overprinting of circum-Pacific tectonics on pre-existing Tethys tec-tonics.Its dynamic mechanism is the sudden onset of high-speed oblique subduction of the Izanagi plate in the Pacific region.