The tectonic setting and petrogenesis of the Paleozoic volcanic rocks, especially the Carboniferous and Permian volcanic rocks in the Beishan orogenic belt are problems of long controversy and have aroused much interest among geologists. The authors consider that the Carboniferous volcanic rocks belong to the andesitic basalt of tholeiite series and the Permian volcanic rocks belong to the andesitic basalt and subalkaline basalt of tholeiite and transition series. The samples collected from the Carboniferous and Permian volcanic rocks are characterized by slight enrichment of LREE and slight fractionation between LREE and HREE. The Carboniferous and Permian volcanic rocks which were contaminated by the crust are highly depleted in Nb, Ta and slightly depleted in Ti, whereas the Carboniferous and Permian volcanic rocks which were not contaminated by the crust are similar to ocean island basalts (OIB) and "hump-shaped" mantle-normalized multi-element patterns without negative Nb and Ta anomalies. The Carboniferous and Permian basaltic rocks were derived from the mantle plume, because some basalts which belong to the Carboniferous and Permian volcanic rocks were obviously contaminated by the crust, exhibiting geochemical characteristics of island-arc or active continental margin basalts. Combined with the research on tectonic evolution in the study area and the related tectonic setting discrimination diagram, the authors have reached the conclusion that the Carboniferous and Permian basalts were all formed in an intraplate setting.