Since the “Snowball Event”, the early life has presented a multilevel, massive evolution, and reached its climax before the eve of the Cambrian. Accompanied the dramatic succession of life, the environment sign of the Earth changed and carbon isotope also shifted dramatically, both of which corresponded to the each stage of life succession. However, a big difference still occurs in the division of the most important geological boundaries, PrecambrianCambrian stratotype section and point (“Golden Nail”, GSSP). Treptichnus pedum as a marker fossil of the GSSP has been questioned constantly in the global biostratigraphic division (especially in Siberia and South China), partially due to the fact that remains of trace fossils as a symbol also has certain defects. The earliest skeletal fossil Cloudina and the body fossil Shaanxilithes in South China can be well compared on a global scale, and the appearance of these two fossils corresponds to significant positive excursions of carbon isotope. By studying the stratigraphic distribution and geographical distribution characteristics of the fossil zone, this paper analyzes the spatiotemporal features and evolutional significance of the system, and discusses the potentials of Cloudina and Shaanxilithe as markers of Cambrian bottom. Finally, a more ideal standard is proposed to determine the PrecambrianCambrian boundary.