In this article, the author did systematical zircon U-Pb dating and rock analysis test. It is considered that those rock bodies has characteristics of superacid, alkali-rich, weak peraluminous, poor sodium and rich potassium, which belonged to magmatic rocks of shoshonite series with superacid, alkali-rich. It shows that those rocks have rich light rare earth and poor heavy rare earth, which belong to post-collision granitoid rocks, in accordance with geochemical characteristics of rich molybdenum, intermediate-acid rock bodies in east Qinling-Dabie molybdenum polymetallic metallogenic belt. （La/Yb）N is between 10.65~20.53. δEu has medium negative anomaly. It has U type of high left and flat dip right in rare earth element distribution curve figure. Weighted average age is 138.7±0.86Ma（1σ，n=8，MSWD=0.87）in porphyry-like granite body of Xiaofan rock bodies by using LA-ICP-MS zircon U-Pb dating, which represents the age of crystallization for rock bodies. The research suggests that Xiaofan rock bodies are not the evolution product of Lingshan granite batholiths homologous magma. Xiaofan and Lingshan rock bodies belonged to two different magma activities separately. On the following basis: (1) The age of Xiaofan rock bodies are early 10Ma than that of Lingshan rock bodies. (2) Xiaofan rock bodies originate from magma source region with relatively high temperature and high pressure in lower crust. Thus, Xiaofan rock bodies cannot be the differentiation of Lingshan rock bodies (low temperature magma). The geodynamics background of Xiaofan rock bodies is magma activities which results from Mesozoic tectonic regimes changes and lithosphere large-scale delaminating thinning under post stretching mechanism. In the situation of crust delaminating and mantle material leaching, it has fusion in lower crust of high pressure granulites which include plagioclase-hornblende-garnet-pyroxene. Thus, it forms Xiaofan deep-sourced and hypabyssal type rich molybdenum (copper) granite rock bodies.