Abstract:The study of the mineralogical,petrochemical and geochemical varuations of monzonito-granutic xenoliths resorbed in the shihlunite indicates that a fused mass, which is riched in potassium and other incompatible mantle elemeats, could not be produced by resorption of these xenoliths. Accordinglly, it should be considered that the hypothesis proposed by Gorai, interpret吨the shihlunite as a product of soda-alkalic basalt magma contaminating granite, could neither explain the petxochemical, geochemical and geological characteristic of shihlu- niter nor consist with the conclusion of experimental petrology. It is indicated that shihlunite may have been derived from a kind of primary potassic magma which was formed as a result of lower degree of partial melting of phlogopite- rich mantle rocks in the deeer layer of the upper mantle. And the contam- ination of granite could only decrease the basicity of the rock.