The Muchang A-type granite is a composite intrusive body consisting of the riebeckite nordmarkite, riebeckite granite and aegirine granite. Its formation related to riftogenesis. The differential degree of the body is rather high: rich in alkali and Fe, poor in Mg and Ca. The abundance of REE is relatively high. The fractionation of LREE is very intense and with the evident negntive ano- maly of Eu.The Muchang A-type granite is a congeneric product with the Upper Permian volcanic sequences formed by the mixing of basaltic magma and partial anatectic magma of the continental crust.