This paper provided zircon U- Pb age, petrographic and geochemical characteristics of the volcanic rocks of Manitu Formation in Gongnongtun area, southern Great Hinggan Mountains. meanwhile, Discussing the formation age, genesis and odsgeological significance of the rocks. Methods: Based on the field work, through the microscope observation, the whole rock chemical analysis and zircon U- Pb dating of the volcanic rocks of Manitu Formation in Gongnongtun area, southern Great Hinggan Mountains. Results: Zircon U- Pb dating results show that the age of volcanic rocks is 149.0 ± 1. 1Ma. The Formation age is late Jurassic. The geochemical characteristics show that SiO2 (58. 14% ~ 63. 69%), Al2O3(16. 31% ~ 18. 66%), Fe2O3(3. 17% ~ 5. 39%), K2O + Na2O (6. 58% ~ 7. 86%), MgO (0. 82% ~ 2. 04%), Mg# (25 ~ 41). The andesite of manitu Formation in the study area belongs to quasi aluminous weak peraluminous high potassium calc alkaline rock. The total amount of rare earth elements is 136. 41 × 10-6~163. 64 × 10-6；The ratio of light rare earth to heavy rare earth elements is 7. 22 ~ 10. 02, with an average of 8. 42. (La / Yb) N is 7. 70 ~ 10. 44, with an average of 8. 95; (La / Sm) N is 3. 18 ~ 3. 77; therefore, it can be seen that the enrichment degree of light rare earth elements is higher than that of rare earth elements, and there is obvious fractionation in light and light rare earth elements. δEu is 0. 84 ~ 0. 90, with an average of 0. 87. It shows a weak negative europium anomaly; The distribution pattern of rare earth elements is right inclined. Enrichment of large ion lithophile elements Ba, Th and K; The high field strength elements Ti, P and Nb are relatively deficient. Nb / Ta is 13. 63 ~ 18. 04. Rb / Sr is 0. 10 ~ 0. 16. Conclusion: The petrogenesis may be the partial melting of ferromagnetic rocks in the lower crust and the addition of subduction fluid during the westward subduction of the Pacific plate. The tectonic environment is an active continental margin environment, which is related to the extension after the subduction of the ancient Pacific plate to the West.