It is usually thought that the Mesozoic magmatism in eastern China was related to the westward subduction of the Pacific plate. However, the researches conducted by the author show that eastern China did not belong to circum-Pacific tectonic belt in Mesozoic. It was not in the Andean active continental margin tectonic environment, and there were no island arc basalts and island arc granites. Lots of research work shows that the Pacific plate basically subducted northward in the early Mesozoic and turned to west in the middle early Cretaceous (at about 125 Ma). The large-scale magmatism in eastern China mainly occurred in Jurassic-early Cretaceous period (about 180～130 Ma), and during this period the Pacific plate basically subducted northward. Therefore, the Mesozoic large-scale magmatism in eastern China was not related to the subduction of the Pacific plate. The westward subduction of the Pacific plate only lasted for a very short period, i.e., during 125～110 Ma and 43～0 Ma. During 125～110 Ma, magmatism of eastern China was confined to the east coast of China; during 43～0 Ma, the magmatism in eastern China was almost gone. So the proposition that Mesozoic magmatism in eastern China was related to the westward subduction of the Pacific plate is a wrong unwarranted proposition.