The Kezirto pluton is located in the alkaline intrusive rock belt on the northern margin of the Tarim Basin. The lithology is alkaline granite. The petrogeochemical characteristics were studied in detail. The U-Pb isotope age of the pluton was measured by LA-ICP-MS method, which provides a basis for the study of the characteristics, age, genesis and formation environment of the pluton. At the same time, the nature of late Paleozoic magmatic activities and their tectonic settings in the area were studied, which can better guide the exploration work in the area and have important theoretical and practical significance. The Kezirto granite pluton was divided into two parts, north and south. The total rare earth element content is relatively high. The ∑REE of the northern pluton was 261. 723 × 10 - 6 ~ 834. 783 × 10 - 6 , and the ∑ REE of the southern pluton is 422. 174 × 10 - 6 ~ 575. 86 × 10 - 6 . HFSE ( high field strength elements) are obviously enriched relative to LILE ( large ion lithophile elements) , and elements such as Ba, Sr, P, and Ti are obviously depleted, with obvious negative Eu anomalies. The chondrite-normalized rare earth element diagram shows a slightly right- inclined seagull-like shape, and light rare earth elements are slightly enriched compared to heavy rare earth elements. The Kezirto pluton is A1-type granite. The LA-ICP-MS U-Pb isotope ages of the north and south plutons are (273. 8 ± 2. 9) Ma and (274. 8 ± 1. 8) Ma, which are contemporaneous plutons. The formation of the Kezirto pluton is due to the underplating of mantle-derived magma, which leads to the remelting of ancient rocks in the lower crust. After that, it undergoes fractional crystallization. During the formation process, it is contaminated by the crust to different degrees. The pluton has experienced the tectonic environment of deep mantle plume and intracontinental rift.