Objective To explore the effects of early nutritional support on immune function in postoperative patients with lung cancer. Methods Totally 84 cases of patients with lung cancer operation from May 2013 to May 2015 were selected and assigned to the control group and the observation group randomly, and 42 cases in each group. Patients in the control group were given routine nursing method, while patients in the observation group were given additional early nutritional support.Results Hospitalization time in the observation group was (9.73±2.18) d, while it in the control group was (12.52±3.46) (t=-4.42,P<0.01). 3 months after operation, the IgA (1.9±0.4) g/L, IgM(1.5±0.4) g/L, IgG (12.5±1.6) g/L and serum albumin (35.7± 5.2) g/L were all superior than that in the control group (t=2.59,2.90,3.96,2.81;P<0.05).Conclusions Early nutritional support is helpful in patients with lung cancer after chemotherapy for the restoration of nutritional and immune function, and it can improve the quality of life after operation.