Jingdingshan volcanic rocks occur in the eastern part of West Kunlun Mountain in North Tibet Plateau, geotectonically on the southern margin of the suture zone between North China plate and South China plate. The rocks originated from typical continental central eruption characterized by more than three times of volcanic activities. They overlie abruptly declining Palaeogene Aletars Formation (E3a) in the form of gentle la-va sheet and have been subjected to slight erosion. K_Ar isotopic age is 0.45~1.93 Ma. Latite, the main vol-canic rock, is of calc-alkaline series in the sub-alkaline series: SiO257.88%~60.82%, MgO 1.95%~2.2%,Na2O+K2O 6.93%~7.27%,δ2.73~3.1, andDI63.5~64.6. The large_ion lithophile elements are highly concentrated, while the high_field intensity elements are comparatively less concentrated. REE 650×10-6~766×10-6and LREE/HREE 14.9~15.7 point to intensely-concentrated LREE.δEu values are 0.75~0.89,(87Sr/86Sr) is 0.70970 andδ18O is 10.4‰. A comprehensive study shows that the magma came from partly, melting magma in the lower crust or the transitional zone between the crust and the mantle, whereas the vol-canic rocks were formed in a post-collision uplifted extensional setting.