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The Baojinshan gold deposit is a Au-dominated polymetallic deposit discovered recently in central Hunan, its mineralisation is considered to be closely related to the magmatic activities in late Indosinian. High accuracy SIMS zircon U-Pb age determination was used in this study to obtain the ages of two granodiorite-porphyry dykes at (225.1±1.5) Ma and (223.3±1.4) Ma, indicating that this deposit was the product of extensive magma activity in late Indosinian. The 176Hf/177Hf values of two granodiorite-porphyry dykes intensively distributed around 0.2825, with the corresponding epsilonHf(t) ranging from -5.9 to 3, av. -3.98. The TDM2 model age was estimated from 0.96 GPa to 1.45 Ga, av. 1.35 Ga; the delta18O value of granodiorite-porphyry ranged from 0.824% to 0.973%. Hf-O isotope analysis shows that the granodiorite-porphyry is mainly formed by the rock remelting of Mesoproterozoic lower crust, and mantle-sourced materials are considered to participate in diagenesis. Contrastive analysis on the granodiorite-porphyry in Baojinshan with Ziyunshan granite suggests that both of them are the products of comagmatic evolution, which indirectly indicates that the metallogenetic time of Baojinshan gold deposit ranges from 227 to 223 Ma. The granodiorite-porphyry is formed under the multi-plates convergent dynamics background, and affected by the northward squeeze of Indochina Block and westward subduction of Pacific Plate., The Baojinshan gold deposit is a Au-dominated polymetallic deposit discovered recently in central Hunan, its mineralisation is considered to be closely related to the magmatic activities in late Indosinian. High accuracy SIMS zircon U-Pb age determination was used in this study to obtain the ages of two granodiorite-porphyry dykes at (225.1±1.5) Ma and (223.3±1.4) Ma, indicating that this deposit was the product of extensive magma activity in late Indosinian. The 176Hf/177Hf values of two granodiorite-porphyry dykes intensively distributed around 0.2825, with the corresponding epsilonHf(t) ranging from -5.9 to 3, av. -3.98. The TDM2 model age was estimated from 0.96 GPa to 1.45 Ga, av. 1.35 Ga; the delta18O value of granodiorite-porphyry ranged from 0.824% to 0.973%. Hf-O isotope analysis shows that the granodiorite-porphyry is mainly formed by the rock remelting of Mesoproterozoic lower crust, and mantle-sourced materials are considered to participate in diagenesis. Contrastive analysis on the granodiorite-porphyry in Baojinshan with Ziyunshan granite suggests that both of them are the products of comagmatic evolution, which indirectly indicates that the metallogenetic time of Baojinshan gold deposit ranges from 227 to 223 Ma. The granodiorite-porphyry is formed under the multi-plates convergent dynamics background, and affected by the northward squeeze of Indochina Block and westward subduction of Pacific Plate.