Abstract: OBJECTIVE To discuss the risk factors for infection of lung cancer patients during chemotherapy, and explore the clinical significance of the content of inflammatory factors in blood. METHODS 156 cases of lung cancer patients undergoing chemotherapy from Jan. 2012 to May 2015 were enrolled in the study, and divided into the lung cancer with infection group (n=35) and lung cancer group (n=121) according to whether there was combination with infection. The incidence of infection during chemotherapy was compared in patients with different factors including age, gender, length of hospital stay, chemotherapy cycle, tumor type and invasive operation. Multifactor logistic regression analysis was performed for infection in patients with lung cancer during chemotherapy. Blood samples were collected from patients in the lung cancer with infection group at the occurrence of infection and after anti-infective treatment. After centrifugation, plasma was isolated and ELISA was used to detect the levels of PCT, IL-1, IL-6 and TNF-αin plasma. RESULTS Multivariate logistic regression analysis results showed that the length of hospital stay≥14 d, chemotherapy cycle of ≥2, tumor types of central types or diffuse types, invasive operation, smoking, white blood cell count of ≥3.0×10⁹ /L were independent risk factors of infection during chemotherapy in patients with lung cancer(P<0.05).After anti-infective treatment, the blood levels of PT, IL-1, IL-6, TNF-α levels in patients with lung cancer combined with infection were all significantly lower than before treatment (P<0.05). CONCLUSION This study suggests that hospitalization time, chemotherapy cycle, tumor types, invasive procedure, smoking, and white blood cell count are associated with infection during chemotherapy in patients with lung cancer. Inflammatory factors in bloodare good indicators for the determination of infection in patients with lung cancer.