Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South China, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13 C background values are intensively controlled by palaeogeographic environment. In general, δ 13 C values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the InduanOlenekian boundary and the Lower Triassic-Middle Triassic boundary.The Early Triassic is a critical period in earth history. A series of events such as volcano eruptions [1,2] , sea-level fluctuations, changes in environmental conditions [3] , mass extinctions [4,5] as well as global negative carbon isotope excursions [6 -9] have been discovered in the uppermost Permian or across the Permian-Triassic boundary. Large scale sea-level rise [10][11][12] , restoration of environment conditions, recovery of ecosystem [13] , including gradual carbon isotope rise [14] occurred in the East Tethyan Ocean in the early Triassic after the mass extinction. In order to describe the features of carbon isotope evolutions in detail, construct evolutional pattern of carbon isotope compositions, discuss the controlling factors on carbon isotope evolution, three sections located on the carbonate platform, deep-water slope and in deep-water