There is a lot of diabase in southern part of Shaanxi Province. The lithological composition formed in continental margin rift valley. The magmas derived from the lower crust and upper mantle. The titanomagnetite related to the diabase in Ziyang-Langao area has formed large-scale with a beneficial component can be recycled. Ore bodies are hosted in the early Paleozoic strata in the basic diabase. Usually the large-scale of the rock mass has differentiation. Titanomagnetite mineralized obviously in the rock mass with obvious differentiation. The larger-scale and the better differentiation diabase is more helpful for prospecting.