Abstract: The intermediate-acidic intrusive rocks exposed in the western part of the Biezhentao mountains area in Xinjiang are mainly composed of granite, granodiorite and amphibolite. In this contribution, petrological, zircon U-Pb isotope chronology and Hf isotope studies were carried out for different lithologies of intrusive rocks in the study area to constrain their petrogenesis, and tectonic setting. The zircon U-Pb dating results show that the granite, granodiorite and two diorite samples have weighted average ages of 460.2 Ma, 458.4 Ma and 403.3-402.2 Ma, respectively, and the granite and granodiorite intruded in the Middle-Late Ordovician, while the amphibolite intruded in the Early Devonian. In terms of geochemical composition, the three types of rocks exhibit enrichment in LREE, LILE, and deficit in HREE, HSFE, indicating that the three types of rocks may be formed in the magmatic arc environment under the subduction background. The zircon Hf isotopic characteristics of granodiorite and diorite show a trend of transition from depleted mantle to chondrite, with zircon ε_Hf(t) values ranging from −2.4 to 8.7 and −2.5 to 3.5, respectively, and the two-stage Hf model ages are much older than the intrusive time. In addition, the granite of the west section of the Beizhentao suite is high in Sr, low in Y and Yb, with typical adakite features, formed by partial melting of the thickened lower crust and accounted for by subduction plate fluids. Granodiorite is a peraluminous calc-alkaline series rock, which belongs to I-type granite. Its Mg^# is 28.9 ~ 31.0, which is formed by partial melting of mantle-derived new lower crust. The diorite belongs to the quasi-aluminum calc-alkaline series rock, with Mg^# between 17.3 and 22.1, which is also formed by partial melting of the mantle-derived new lower crust, but it may be the product under the background of regional local extension. The Early Paleozoic intermediate-acid intrusive rocks in the Biezhentaoshan area of the Western Tianshan Mountains are magmatic products of the subduction of the North Tianshan Ocean under the southern Yili plate from the Middle-Late Ordovician to the Early Devonian, indicating the environment of the continental margin magmatic arc.