Abstract: The Alar rock is composed of Hercynian biotite granite and Indosinian K-feldspar granite, which have a number of pegmatite veins around it. The pegmatite type evolution gets stronger gradually from inner to exterior, and rare metal metals mineralization also evolves from simple to the complex. The formation era and magmatic metallogenic series of granite basically correspond with those of the pegmatite. It is concluded that based on Alar porphyraceous biotite granite, these pegmatite veins are satellite rock produced by regenerated magma intruding along the edge of the Alar biotite or they may be formed by pulsing injection of series of magma with many different components during Alar rock magmatic differentiation evolution. The big time span of magmatic evolution, together with multi-unit rock composition interactive transitional output and favorable faults tectonic environment are the important conditions for rare metal pegmatite output.