Objective:To investigate the diagnostic value of Flt3 ligand (Flt3L) and growth arrest specific protein 6 (Gas6) in post-chemotherapy infection of patients with non-Hodgkin′s lymphoma.Methods:A total of 94 NHL patients admitted to Wuhan No.1 Hospital for chemotherapy from July 2019 to October 2020 were collected, and divided into infection group ( n=40) and non-infection group ( n=54). Fifty healthy subjects at the same period were selected as the control group to analyze the expression levels of Flt3L, Gas6 and general inflammatory indicators among the three groups. The relationship between Flt3L, Gas6 and general inflammatory indicators were analyzed. The predictive value of Flt3L and Gas6 for post-chemotherapy infection in NHL patients was analyzed by ROC curve. Kaplan-Meier curve was used to analyze the infection status of NHL chemotherapy patients with serum Flt3L and Gas6 levels. Results:The levels of serum Flt3L [807.80(215.10-1 232.00) pg/ml] and Gas6 [20.04(13.14-27.52) ng/ml] in the infection group were higher than those in the non-infection group and the control group, and the differences were statistically significant (all P<0.05);The levels of serum Flt3L[887.3(321.60-1 367.00) pg/ml] and Gas6[25.24(17.61-42.86) ng/ml] in the severely infection group were higher than those in the mildly infection group, and the differences were statistically significant (all P<0.05). serum Flt3L was negatively correlated with WBC and positively correlated with IL-6;serum Gas6 was negatively correlated with WBC.ROC curve analysis showed that the AUC and 95% CI of Flt3L and Gas6 were 0.814 (0.718-0.909) and 0.644 (0.523-0.765), respectively. The combined application of serum Flt3L with hsCRP, PCT and IL-6 significantly improved the diagnostic efficiency, and the area under the curve was 0.956, 0.923 and 0.865, respectively. Kaplan-Meier curve analysis showed that when serum Flt3L≥649.80 pg/ml and serum Gas6≥21.50 ng/ml in NHL chemotherapy patients, the infection rate was significantly increased ( P all<0.05). Conclusion:Serum Flt3L and Gas6 levels in post chemotherapy-infection of NHL patients were significantly increased and correlated with the severity of infection. Early detection of serum Flt3L levels is helpful to predict the diagnosis of infection in NHL patients after chemotherapy.