The North China Craton is the most obvious and most typical area for the study of the destruction of the craton. The timing, scale and geodynamics of decratonization are hot issues among the geoscientists both in China and abroad. Large-scale magmatism is one of the geological responses to decratonization. The ages, sources of magmas and petrogenetic processes of magmatic rocks can be used to constrain the timing, scale and possible geodynamics of decratonization. Mesozoic intrusive rocks are widely distributed in the eastern North China Craton. Based on research works conducted in the past ten years or so, the authors summarize zircon U-Pb ages of the Mesozoic intrusive rocks in eastern North China Craton, which show mainly three stages of magmatism in eastern North China Craton, i.e., Triassic, Jurassic and Early Cretaceous. Geochemical features were used to trace their magma sources and petrogenesis, and the transition of the nature and thickness of the lithosphere and the spatial scale of decratonization were further constrained. On such a basis, the possible geodynamic mechanism of decratonization of the North China Craton is discussed in combination with regional geology.