Abstract： Objective To investigate the distribution characteristics of fungal infection and the risk factors of fungal infection in patients with thoracic tumor after radiotherapy and chemotherapy.Methods Sixty patients with fungal infection after radiotherapy and chemotherapy for thoracic malignant tumors(fungal group)were selected from January 2020 to January 2022 in Huangshi Central Hospital,and 180 patients without pathogen infection after radiotherapy and chemotherapy(no infection group)were selected as the control,the distribu-tion of fungal infection and drug sensitivity were analyzed,as well as the differences in clinical data between fungal group and no infection group.Results Respiratory tract infection was the most common fungal infec-tion,accounting for 50.00％,Candida albicans was the main fungal species,accounting for 53.33％.Candida al-bicans,Candida tropicalis and Candida glabrata were resistant to antifungal drugs to varying degrees,among which the resistance rate to ketoconazole was the highest,reaching 21.88％,28.57％and 37.50％respectively.The proportion of patients with age＞50 years old,diabetes,clinical stage Ⅲ～Ⅳ,invasive operation,hormone use,antibiotic use time＞14 days,antibiotic use types≥2,KPS score＜80,Hb level＜1 10g/l,ALB level＜40g/l in fungal group were 65.00％,46.67％,68.33％,55.00％,56.67％,48.33％,60.00％,45.00％,35.00％and 36.67％respectively,which were significantly higher than those in no infection group(P＜0.05).Logistic re-gression analysis showed that age,diabetes,clinical stage,invasive operation,type of antibiotics used,KPS score were the influencing factors of fungal infection in patients with thoracic tumor after radiotherapy and chemotherapy(P＞0.05).Conclusion Fungal infection after radiotherapy and chemotherapy in patients with chest tumors is mainly Candida albicans,and the occurrence of fungal infection is mainly influenced by various factors,including patient age,diabetes mellitus,clinical stage,invasive operation,type of antibiotic use,and KPS score.