As the final evolution product of the sodic alkaline rocks in the continental volcanic province, study on the petrogenesis of phonolite is of great significance for understanding the magmatic evolution process of the continental volcanic province. This study focuses on the phonolite exposed in the Tuoyun Mesozoic-Cenozoic volcanic basin in the southwestern Tianshan Mountain, China. We carried out detailed mineralogical, petrological and geochemical studies on the phonolite, with the aims to reveal the Tuoyun magma series and magmatic evolution processes. Tuoyun phonolite is characterized by the presence of alkaline feldspar, clinopyroxene, fayalite and amphibole phenocrysts, while the nepheline occasionally occurs in the groundmass. In terms of geochemical composition, Tuoyun phonolite is characterized by high Na2O (7.9-8.6 wt.%) and K2O (5.2-6.3 wt.%). The total rare earth element (REE) of Tuoyun phonolite ranges from 408 to 470ppm, and the chondrite-normalized REE patterns have obvious Eu anomaly. On the primitive mantle-normalized trace elemental spider diagrams, the samples show negative anomalies of Ba, Sr, P, Ti and positive anomalies of Nb, Ta, Zr and Hf. The depleted Nd isotopic compositions show that phonolite is genetically related to the associated basanite. Based on the MELTS thermodynamic simulation, the phonolite could be produced by the basanite after fractionation of feldspar (36%), clinopyroxene (21%), spinel (10%), olivine (6%) and amphibole (5%). Further EC-AFC modeling exhibits that the phonolite has suffered crust contamination to some degrees (~10%) during the evolution. Our study revealed that the Tuoyun volcanic rocks belong to the peralkaline series of basanite-phonotephrite-phonolite, and the phonolite may represents the final evolution product of the peralkaline rock series in Tuoyun volcanic basin.