Abstract: A set of mafic−ultramafic rocks emerged from the Early Paleozoic volcano−sedimentary strata in the Wolihe of Duobaoshan area, northern part of the Greater Khingan Mountains, whose formation age and structural properties are still unclear.In this paper, petrology, petrogeochemistry and zircon U−Pb (LA−MC−ICP−MS) chronology are used to systematically study the set of mafic−ultramafic rocks.The results show that the mafic−ultramafic rocks include serpentinite, serpentinized pyroxene peridotite, altered gabbro, hornblende gabbro, basaltic andesite and pillow basalt, which have the characteristics of ophiolite combination; The first two are mantle rocks, gabbro has the characteristics of cumulates, basalt andesite is equivalent to basic dike, pillow basalt is submarine extruded rock; They are distributed in the matrix of Early Paleozoic stratified pyroclastic rock and clastic sedimentary rock, and together constitute a set of ophiolitic mellitic rocks.Among them, mafic rocks belong to the calc−alkaline series,ultramafic rocks and mafic rocks are rich in large ion lithophile elements Ba, K, Sr, and depleted in high field strength elements Nb, P, Ti and Th, which have the characteristics of active continental margin arc volcanic rocks.The formation age of basalt andesite in the upper unit of ophiolite is 447 Ma.In summary, it is considered that the ophiolite belongs to suprasubduction zone type ophiolite (SSZ), which formed in the tectonic setting of the arc back basin. The youngest geological body of the ophiolite tectonic emplacement is the Early to Middle Ordovician, and it is speculated that the ophiolite tectonic emplacement is located at the end of the late Ordovician, it is inferred that the ophiolite tectonic emplacement was at the end of the Late Ordovician.