Volcanicrocks from Manitu Formation in Hanbumiao area, Inner Mongolia, the Western Great Xing’an〖JP〗 Range mainly consists of andesite and dacite. LA- ICP- MS zircon U- Pb dating yields the Late Jurassic age of 153.4±0.8Ma for the andesite and 155.6±0.6Ma for the dacite. Volcanic rocks from Manitu Formation in Hanbumiao area are rich in alkali (K2O+Na2O=4.70~10.47%), suggesting a high- K calc- alkaline series magma with the peraluminous feature (A/CNK=0.83~1.95).The rocks are rather high in rare earth elements(REE=122.72×10-6~416.68×10-6), enriched in LREE\[(La/Yb)N=10.85~60. 04\] and LILEs (Rb, Ba)，and depleted in HFSE, especially Nb, Ta, P, Ti, Y, and weak negative Eu anomalies(δEu=0.71~0.87). These characteristics are similar to those of continental marginal arc volcanic rocks. These new age and rock geochemical data indicate that the Manitu volcanic rocks in Hanbumiao area were generated in a continental marginal arc tectonic setting in response to the Pacific Ocean subduction.