The bimodal volcanic rocks of Upper Carboniferous Yishijilike Formation from the Tekes Daban area in Yining landmass consist mainly of basalts and rhyolites. Their SiO₂ values range from 47.13% to 77.72%, and exhibit a gap of SiO₂ between 53.62% and 72.15%, displaying a typical bimodal geochemical affinity. The LA-ICP-MS zircon U-Pb ages of rhylites yielded an age of 302.8±3.6 Ma, suggesting that these bimodal volcanic rocks were formed at the beginning of Late Carboniferous. Basalt samples have SiO₂ values of 47.13%~53.62%, with high Fe₂O₃ (TFe₂O₃ being 10.90%~17.40%) and MgO (3.74%~10.12%, 6.48% on average), high Na (2.84%~6.69%) and low K (0.48%~3.77%) values. The basalts are obviously enriched in light rare earth elements and depleted in heavy rare earth elements[(La/Yb)_N=1.58~4.94]. In contrast, the rhyolites samples have SiO₂ values of 72.15%~77.72%, high K (6.12%~9.48%) and low Na (0.40%~2.39%) concentrations. Compared with the basalts of bimodal volcanic rocks, they show significant depletion of Ba, Sr, P, Ti elements, obvious enrichment of light rare earth elements and relative depletion of heavy rare earth elements. They exhibit strongly negative Eu anomaly (δEu=0.18~0.44) and geochemical characteristics of A2 type granites. In addition, the basalts have high values of Mg^#, Co, Cr, Ni, with εNd(t) of basalt samples being 3.45 and 3.55. These features indicate that basaltic magmas were derived from partial melting of a depleted mantle source. The rhyolites of the Yishkilike Formation have low Mg^# and positive εHf(t) values, suggesting that their formation was related to crustal melting during the process of basaltic magma underplating. Combined with the two-stage Hf model ages, it is suggested that the rhyolite source may be related to the reworking of Proterozoic metamorphic basement. These geochemical characteristics together with structural tectonic discriminant diagrams show that the bimodal volcanic rocks of the Yishijilike Formation were formed in a post-orogenic extensional environment with intraplate genetic characteristics. The discovery of the typical bimodal volcanic rocks provides important information for further study of the Carboniferous tectonic evolution in Yining landmass.