Abstract: The Mengjiatun Formation complex is a suite of supracrustal rocks formed in the early Neoarchean, and its typical rocks include garnet quartzite, biotite-quartz schist and amphibolite. Petrographic and REE and trace element geochemical studies of these rocks and Nd isotope analysis of amphibolite indicate that the protoliths of the Mengjiatun Formation complex are sandstone, mud-rich sandstone and island arc tholeiite. This view has great significance for the study of the formation and evolution of the early Precambrian crust in western Shandong.