The Tong'an Formation, Hekou and Dongchuan groups, deposited during early to middle Mesoproterozoic, are important stratigraphic units on the Yangtze block. Their depositional age and tectonic attributes, however, remain in dispute. In this study, new regional geological evidences and geochronological data allow us to redefine the depositional age and tectonic attributes of the Tong'an Formation, Hekou and Dongchuan groups using the "Ocean plate stratigraphy" theory. The Tong’an Formation is an ophiolite complex that consists of different scale blocks and strong deformed matrix. Accordingly, the Tong’an Formation has been defined as the Caiziyuan- Tong’an ophiolite mélange. The stratigraphic sequence of the Dongchuan Group records a complete evolution from the intracontinental rift to the passive continental margin, and represents the basin marginal deposits. Although it outcrops on different fault blocks with the Caiziyuan- Tong’an ophiolite mélange, they were deposited in a same basin. The Hekou Group has obviously different stratigraphic sequence from the Dongchuan Group and the Caiziyuan- Tong’an ophiolite mélange, with a transgressive sequence of sediment grain size finer upwards and several volcanic layers. The Hekou Group could have been deposited in a failed rift in the context of breakup of the Columbia supercontinent. The garnet mica schist is from the Changchong Formation of the Hekou Group. Zircon grains from the schist exhibit core- rim structures. Zircon LA- ICP- MS U- Pb dating results from the zircon cores shows that the youngest age cluster yielded a weighted mean 207Pb/206Pb age of 1468 ± 28 Ma (MSWD=0.40, n=16), which is interpreted as the maximum depositional age of the garnet mica schist. Combined with existing geochronological data, the depositional age of the Hekou Group and Dongchuan Group were limited to 1.75～1.40 Ga and 1.75～1.35 Ga respectively. Meanwhile, the metamorphic age from zircon rims concentrated in ca. 830 Ma. The spongeous structure on zircon CL images reveals that the metamorphic rims is most likely a product of hydrothermal alteration. Zircon grains of 2.0～1.8 Ga mostly give negative εHf(t) values, indicating that the magmatism is dominated by the recycling of the ancient crust in the southwestern Yangtze Block; while zircon grains of 1.58～1.39 Ga are dominated by positive εHf(t) values, suggesting that a large amount of mantle material has entered. Our comprehensive study identified four evolution stages of the southwestern Yangtze Block during late Paleoproterozoic and early to middle Mesoproterozoic: collisional orogenesis during 2.00～1.80 Ga, intracontinental rifting during 1.77～1.64 Ga, passive continental margin basin in 1.58～1.39 Ga and subduction and extinction of the oceanic crust since 1.38 Ga.