This paper presents detailed petrological, zircon U- Pb chronological, whole- rock geochemical and Sr- Nd- Hf isotopic studies on the Permian- Triassic granitic intrusions in Huade County, Inner Mongolia. The geochemical and isotopic features indicate that the studied intrusions were derived from a Paleo- to Mesoproterozoic crustal source of the North China craton. The Bayinchahan intrusions experienced magma mixing during the magma upwelling. The Baiyintla intrusions were S- type granite formed by partial melting of metamorphic greywacke during crustal thickening, the Maohuqing intrusions were I- type granite, the Kangjiadi and the Zhangwanliang intrusions were A- type granite. Zircon dating results indicate that the Bayinchahan, Baiyintela, Maohuqing, Zhangwanliang and Kangjiadi plutons were formed in the Early Permian (276±1 Ma), the Middle Permian (270±1 Ma), the Late Permian (254±1 Ma), the Early Triassic (248±1 Ma) and the Late Triassic (229±1 Ma), respectively. Combined with previous studies, we conclude that the study area experienced subduction, subduction- collision, continuous collision and post- orogenic extension during the Early Permian to Late Triassic. The closing time of the eastern part of the Paleo- Asian Ocean in the study area should be the late Middle Permian.