嗜酸性粒细胞属于固有免疫细胞，有助于防御寄生虫、细菌和病毒感染，特别是在过敏反应中发挥重要效应。嗜酸性粒细胞浸润多种肿瘤，通过直接与肿瘤细胞相互作用或在肿瘤微环境中间接调节肿瘤进展。嗜酸性粒细胞能够合成和分泌嗜酸性粒细胞碱性蛋白、嗜酸性粒细胞过氧化物酶和嗜酸性粒细胞阳离子蛋白等参与抗肿瘤效应，亦可通过促进炎症进展等方式促进肿瘤形成。为此，文章重点探讨嗜酸性粒细胞在肿瘤发生发展中的生物学作用，及作为免疫治疗的预测靶标，对临床疾病治疗和监控的作用。“,”Eosinophils are innate immune cells that help defend against parasitic, bacterial and viral infections, especially play an important role in allergic reactions. Eosinophils infiltrate many tumors and regulate tumor progression either directly by interacting with tumor cells or indirectly by forming tumor microenvironment. Eosinophils can synthesize and secrete eosinophil basic protein, eosinophil peroxidase and eosinophil cationic protein to participate in the anti-tumor effect, and also promote tumor formation by promoting inflammatory progression and other ways. Therefore, this review focuses on the biological role of eosinophils in the development of tumor, and the role of eosinophils in clinical disease treatment and monitoring as a predictive target of immunotherapy.