The present invention relates to novel interleukin 2 (IL-2) mutants and uses thereof. In particular, the present invention relates to IL-2 mutants having reduced IL-2R α receptor binding ability and/or increased IL-2R β receptor binding ability compared to wild type IL-2. The present invention also provides a fusion protein, an immune-conjugate comprising the IL-2 mutant, and a nucleic acid encoding the IL-2 mutant, a vector and a host cell comprising the nucleic acid. The invention further provides a method of making the IL-2 mutant, a pharmaceutical composition comprising the IL-2 mutant, and a therapeutic use of the mutant.本發明涉及新型白介素2(IL-2)突變蛋白及其用途。具體地,本發明涉及,與野生型IL-2相比,具有降低的IL-2R α受體結合能力和/或提高的IL-2R β受體結合能力的IL-2突變蛋白。本發明還提供包含該IL-2突變蛋白的融合蛋白、免疫綴合物,以及編碼該IL-2突變蛋白的核酸、包含該核酸的載體和宿主細胞。本發明進一步提供製備該IL-2突變蛋白的方法、包含該IL-2突變蛋白的醫藥組成物和該突變蛋白的治療用途。