The magmatites are divided into two diagenetic series in Gejiu area according to magma source, lithofacies, physicochemical characteristics，and genetic coane- ction. They are mantle source differentiation and crust source remeltiag. Mantle source differentiation series experience as evolution from volcanic rock stage to intrusive rock stage. Volcanic stage means the evolution of tholeiites-high-alumina basalts-alkalibasalts. And intrusive rock stage means the evolution of basic rocks-alkaline rocks-porphyry veins. Crust source remelting series contains only anatectic magma stage. It experience the development processes from contaminated granite (porphyritic) to intrusive one (granular texture).