This paper reports a syenogranite from Zhaiwa area in Xiong'er Mountain on the southern margin of North China Craton. The syenogranite yielded a SHRIMP zircon U-Pb age of 217.7±3.6 Ma and MSWD=1.6, showing Mesozoic. The syenogranite is rich in alkaline and Al, but low in Mg and Fe. The trace elements are characterized by obvious depletion of Ba, Sr, P and Ti but relative enrichment of U, Th, Zr and Hf. The REE of Zhaiwa syenogranite has obvious tetrad effect. The geochemical features of the Zhaiwa syenogranite are different from those of the alkali-rich intrusive rocks in east Qinling and the early Mesozoic granitoids in north Qinling tectonic belt and south Qinling tectonic belt. The Zhaiwa syenogranite is a high-fractional Ⅰ-type granite. The tectonic setting for the Zhaiwa syenogranite is a post-collision or post-orogenic tectonic setting.