Located on the east margin of the Ordos Basin in the North China Craton, the Zijinshan alkaline complex,as a typical rock body in the Fenhe alkali-rich intrusive rock zone, consists of monzonite, diopside syenite, melteigite, malignite, nepheline syenite, pseudoleucite porphyry and trachyte porphyry. The results of SHRIMP zircon U-Pb dating, combined with previous researches, suggest that the Zijinshan complex was formed between 138.7 Ma and 125.0 Ma, thus belonging to the early Cretaceous epoch. The Zijinshan complex shows high K,enrichment of alkali, and low Ca and Mg content. These rocks all show high REE content, LREE enrichment, HREE depletion and no obvious Eu anomaly. In the PM-normalized diagram,trace element pattern exhibits enrichment of LILE (Rb, Ba, K, Sr) and LREE and relative depletion of HFSE (Th, U, Nb, Ta, Ti). Whole rocks Sr-Nd isotopic compositions are characterized by the data I_Sr=0.704 228～0.706 313 and εNd(t)=-12.3～-0.5. The monzonite shows a large variation in zircon Hf isotopic compositions with εHf(t)being -20.2～-16.4 and two-stage model ages from 2.22 Ga to 2.46 Ga. It can be inferred that the Zijinshan complex was formed in an extension setting after Mesozoic tectonic regime inversion in the North China Craton. Continuous ashenospheric upwelling caused by the strong stress during tectonic regime inversion resulted in several times of mixing of melts from asthenosphere mantle,lithosphere mantle and lower crust in different proportions, and then mixed magma of each episode migrated upward to the shallow area of the crust to form the Zijinshan complex. The Fenhe alkali-rich intrusive rock zone was formed between 138.7 Ma and 125.0 Ma. It served as the magma evidence of the destruction in the middle and west parts of the North China Craton, which happened almost at the same time as the destruction in the east part. The ashenospheric upwelling in tectonic weak areas caused by the strong stress during tectonic regime inversion led to the large-scale crust-mantle interaction, which might have been the principal mechanism of the Mesozoic destruction in the middle and west part of the North China Craton, and the mantle-derived magma in the crust-mantle interaction was gradually reduced from north to south.