The Cretaceous-Paleogene volcanic rocks in the eastern Bohai Sea distributed along the Tanlu fault zone, and the volcanic rocks in the western Bohai Sea and western Shandong distributed along the NW-trending fault zones. The volcanic rocks were mainly composed of andesite in age of Cretaceous, and of basalt in age of Paleogene, respectively. The basaltic magma came from rich mantle, rich in LREE and large ion lithophile elements, but deficit Ni and Cr. The initial ratio of Sr and Nd isotopic elements showed that the Cretaceous volcanic rocks originated from the second type of rich mantle while the Paleogene volcanic rocks from rich mantle similiar to primary mantle. The large-scale extension and thinning of the lithosphere in the Baohai Sea and western Shandong during Paleogene resulted in the deficit materials from the deep part of upper mantle upwelling, joining the magmatism and contaminating the rich mantle.