Geological and geochemical characteristics of the Early Ordovician volcanic rocks from North Qilian Mountain show that they are of the basalt-andesite association with no acid rocks or volcanic rocks of the shoshonite series. Their geochemical features indicate that they are of the calc-alkaline series characterized by enrichment of LREE and LILE and depletion of HFSE. They were formed in an island-arc environment of moderate maturity, and the volcanic rocks present in Dongshuixia area might have been formed in an intra-arc rift.