Basic and intermediate-acidic igneous rocks were developed during the late Hercynian in North Tarim basin. The geochemistry characteristics of the rocks show that basic volcanic rock has K2O/Na2O = 0.18-0.61 < 1 and falls into a category of basalt of sodium system. The rocks contain en- riched large-ion lithophile elements (LILE) (K, Rb, Ba, Th) and high-field strength elements (HFSE) (Nb, Ta, Ti, Zr, P), with the magmatic material from the upper mantle. The intermediate-acidic volcanic rocks have σ = 1.91-2.96 < 3.3, K2O/Na2O = 1.25-1.59 > 1, as well as the enriched LILE and depleted HFSE (Nb, Ta, Ti, P), presenting the same trace element compositions and character- istics as in the granitic rocks of South Tianshan Mt.; they are either shoshonitic igneous rocks or high-K calc-alkaline igneous rocks, with a distinct crust-derived component feature. The comprehensive analyses on the characteristics of the trace elements, the graphic tectonic dis-crimination, and the distribution features of the two types of igneous rocks show that they were formed under different tectonic settings and geodynamic environments: the basalt was formed in the active rifting period when the active mantle upwelling caused the thinning of lithosphere; the intermediate-acidic volcanic-intrusive rock was formed in the island arc area of the active continental margin in North Tarim; the formation is associated with the plate subduction during the course of South Tian- shan Ocean closure-the subduction of Middle Tianshan Mountain toward the Tarim plate. The basic and intermediate-acidic igneous rocks reveal a tectonic regime of extension-extrusion transition, which is significant in determining the key tectonic revolution period of North Tarim basin. Basic and intermediate-acidic igneous rocks were developed during the late Hercynian in North Tarim basin. The geochemistry characteristics of the rocks show that basic volcanic rock has K2O / Na2O = 0.18-0.61 <1 and falls into a category of basalt of sodium system. The rocks contain en- riched large-ion lithophile elements (LILE) (K, Rb, Ba, Th) and high-field strength elements (HFSE) (Nb, Ta, Ti, Zr, P) Upper mantle. The intermediate-acidic volcanic rocks have σ = 1.91-2.96 <3.3, K2O / Na2O = 1.25-1.59> 1, as well as the enriched LILE and depleted HFSE (Nb, Ta, Ti, P) trace element compositions and character- istics as in the granitic rocks of South Tianshan Mt .; they are either shoshonitic igneous rocks or high-K calc-alkaline igneous rocks, with a distinct crust-derived component feature. The comprehensive analyzes on the characteristics of the trace elements, the graphic tectonic dis-crimination, and the distribution featur es of the two types of igneous rocks show that they were formed under different tectonic settings and geodynamic environments: the basalt was formed in the active rifting period when the active mantle upwelling caused the thinning of lithosphere; the intermediate-acidic volcanic-intrusive rock was formed in the island arc area of ​​the active continental margin in North Tarim; the formation is associated with the plate subduction during the course of South Tian- shan Ocean closure-the subduction of Middle Tianshan Mountain toward the Tarim plate. The basic and intermediate- acidic igneous rocks reveal a tectonic regime of extension-extrusion transition, which is significant in determining the key tectonic revolution period of North Tarim basin.