Abstract: Carboniferous volcanic rocks are widely distributed in northern Alashan League and its neighboring areas, and their genesis and tectonic setting have always been an issue of controversy . Based on analysis of petrology and petrogeochemistry characteristics of Carboniferous volcanic rocks in the study area, this paper attempts to clarify the palaeo-tectonic setting and provides independent evidence for understanding the properties of Carboniferous basin. The volcanic rocks are dominated by intermediate-acidic volcanic rock. The majority of basalts, basaltic-andesite and andesite fall into sub-alkaline series. Mg# number of this suit ranges from 0.29 to 0.69. These volcanic rocks samples exhibit strong depletion in the high field strength elements Nb, Ta and Ti, and minor enrichment in the LREE. In terms of REE, (La/Yb)N number ranges from 2.19 to 10.10, showing less obvious Eu depletion (δEu=0.81 to 1.08), and slightly right-inclined REE distribution patterns, with higher εNd(t) value (+1.10 to +6.35). The samples show not only the marks of those within plate setting as a whole, but also those of subduction zone. Combining with the regional geological characteristic, we conclude that the Carboniferous magmatic activity in the study area generated in a within-plate setting, with variable degrees of contamination of crust during magma ascending, and probably related to mantle plume event.