The Proterozoic non-metamorphic and metamorphic igneous rocks in the northern sector of the Zhongtiao Mountains are products of three stages and five periods of magmatic activities. A comprehensive analysis has been made on the geological, petrological geochemical features of these igneous rocks and the sedimentary facies and metamorphism. The results indicate that in the Proterozoic the northern sector of the Zhongtiao Mountains appeared to be not a simple continental rift but a paleocontinental-margin mobile belt. The intermediate-basic magmatism was an important component part of the Proterozoic crustal evolution. The underplating of mantle-derived basic magma might lead to vertical growth of continental crust. The volcanic activities during two periods were probebly the mechanism of continental crustal horizontal growth.