Huanglongmiao garnet bearing monzogranite is a typical U bearing leucogranite. The leucogranite has features as follow, high silica（73.65%～76.60%）, peraluminous(13.01%～13.80%，A/CNK>1.0)， K rich（4.89%～6.14%）, and the rare earth elements show a distribution of fractionated strongly, with a obviously negative Eu anomaly, while it’s trace elements are distributed as the upper land crust’s do. The granite age is 415.2±2.0Ma, which is obtained from zircon U-Pb , by LA-ICP-MS analyses, And the age indicates a granite in end of Silurian. The granite is partially melt from gneiss bearing garnet biotite and plagioclase in Guozhuang petrofabric of Qinling Group Complex under Post collision setting, it is Calc Alkaline series S type granite. The beginning of post collision is 415~426 Ma of early Paleozoic in eastern Qinling, which is limited by the granite age and regional metamorphism age. At the same time, the granite features indicate that there is no large scale metamorphism and deformation, and the geology evolution turn into a relatively stable process in eastern Qinling Mts. area since early Devonian.