The problem"When did plate tectonics begin?"is one of highly controversial issues at present. In this paper, the different ideas concerning this problem are described on the basis of advanced involving supercontinent,geological criteria of plate tectonics and numerical models. The authors hold that plate tectonicis is not an independent event in the globe in a special period, i.e., it is not a major isochronic thermo-tectonic event. Meanwhile, subduction caused by plate tectonics with lateral movement have occurred since Neoarchean. Few high pressure and ultru-high pressure metamorphic rocks, however, in deep subduction belt occurred at the early stage of plate movement because of a higher mantle temperature. The authors agree with the opinion that the transitional period from proto-style to modern style plate tectonic roughly occurred around the Neoproterozoic.