Objective To study of cellular immune function change of elderly patients with non-small car-cinoma after chemotherapy.Methods 62 patients with non-small carcinoma by age was divided into elderly group (≥60 years old)and youth group (<60 years old).The lymphocytes and their subsets CD3,CD4,CD8 levels were detected respectively in 2 weeks after chemotherapy and chemotherapy before compared with 20 cases of healthy vol-unteers.Results The immune condition of CD3[(51.87 ±2.56)%,(58.98 ±3.87)%]and CD4[(35.01 ± 5.12)%,(42.12 ±3.54)%],CD4/CD8[(0.89 ±0.49)%,(1.08 ±0.86)%]levels were significantly lower than those of healthy controls.Two groups of patients compared with healthy group CD3(69.38 ±8.54)%,CD4(48.21 ± 3.45)%,CD4/CD8(1.87 ±0.85)%(t=10.586,5.998,10.087,6.093,5.170,3.236,all P<0.05),and CD8 [(32.68 ±3.64)%,(30.24 ±2.45)%]levels were higher than those of healthy controls (26.10 ±2.89%)(t=6.777,5.531,all P<0.05);The CD3 and CD4,CD4/CD8 of elderly group patients were markedly lower than that of young patients (t=8.472,6.394,3.059,all P<0.05).The CD8 levels of the elderly group was higher than young patients (t=3.114 2,P<0.05);The Elderly group and young patients after 2 cycles of chemotherapy CD3 signifi-cantly was lower than before treatment (t=10.233,16.847,all P<0.05),but the two groups of patients with CD4, CD8 and CD4/CD8 levels before and after treatment (P>0.05);There was no significant difference with CD3 level of the two groups of patients after chemotherapy (P>0.05);The CD3 level of the two groups of patients after chemo-therapy was no significant difference (P>0.05),the elderly group patients after chemotherapy with CD4 levels was lower than young patients (t=7.130,P<0.05).The CD8 and CD4/CD8 level of the two groups after chemotherapy were no significant difference (P>0.05);The CD3 levels of patient withⅠ-Ⅱ stage were significantly better than patients withⅢ-Ⅳstage (t=1.584,1.721,all P<0.05),the CD4,CD8 and CD4/CD8 level of the two groups had no significant difference(P>0.05).Conclusion The senile non-small carcinoma patients need assistance targeted immunotherapy,also need to adjust according to the patient's age and clinical staging in patients with chemotherapy drug doses.