Abstract: With a systematic study on the basic characteristics, lithogeochemistry and tectonic setting of the volcanic rocks of Baoligaomiao Formation distributed in northern Erenhot-Abagaqi, Inner Mongolia, it is concluded that the volcanic rocks belong to calc-alkaline rock series, formed in synorogenic setting under the control of compression, during the Late Carboniferous orogenic process of intense arc-arc convergence-collision. Due to the oblique convergence effect in the west earlier and east later, the northeast-trending strike slip fault system emerges under the principal compressive stress from northwest to southeast, which provides rising channel and space for the formation of volcanic rocks and leads to strong volcanic eruptions in the extensional tectonic regime of late orogenic stage.