Based on 1∶50000 regional geological survey, the field geological characteristics, petrology, geochemistry and zircon U-Pb chronology of the volcanic rocks of the Upper Jurassic Manitu Formation in Chabuqiri area, Inner Mongolia, central-south Great Hinggan Mountains, were systematically studied by using the triple mapping method of “volcanic structural—litho—lithofacies and volcanic stratigraphy”. The Manitu Formation in Chabuqiri area of Inner Mongolia is divided into two lithologic members. The First Member consists of pyroclastic sedimentary rocks with a small amount of neutral and moderately acidic pyroclastic rocks, and the Second Member consists of neutral lava, pyroclastic rocks with a small amount of pyroclastic sedimentary rocks and acidic pyroclastic rocks, forming a complete sediment-eruption cycle. The volcanic facies are divided into eruption-sedimentary facies, excrete facies, clastic flow accumulation facies, void fall accumulation facies and volcanic channels, and four Ⅴ-class volcanic edifices are outlined. The LA-ICP-MS U-Pb age of the zircons from the andesite in the Second Member of the Manitu Formation in Chabuqiri-manitu Formation is 157. 8±1. 4 Ma, indicating that it was formed in the Late Jurassic. The geochemical characteristics of the trachyandensite in the Second Member of the Manitu Formation are: SiO2= 64. 04%~65. 40%, high Al2O3(16. 02%~16. 96%), rich alkali (K2O+Na2O=8. 07%~8. 38%), low Fe2O3(3. 12%~3. 96%), poor TiO2(0. 6%~0. 81%), A/CNK values between 1. 02~1. 12; the ??REE ranges from 177. 6×10-6 to 254. 6×10-6, with obvious differentiation between light and heavy rare earth, (La/Yb)N=8. 13~12. 63, and a weak negative Eu anomaly (δEu= 0. 71~0. 78); the trace elements are characterized by rich large ion lithophile elements (Rb, Ba, Th, U, K) and relatively deficient high field strength elements (Nb, Ta, P, Ti). The geochemical characteristics of main elements and trace elements show that the trachyandensite of the Second Member of the Manitu Formation in Chabuqi area is shoshonitic series rock. The volcanic magma of the Manitu Formation in Chabuqi area originates from the partial melting of the continental lithospheric mantle triggered by extensional process, and is less affected by crustal mixing, which may have formed in the extensional tectonic setting after the Mongolian-Okhotsk Ocean orogeny.