Abstract: Objective To investigate the efficacy and toxicity of single agent and platinumbased dual drugs chemotherapy for elderly and comorbidity patients with advanced non-small cell lung cancer （NSCLC）. Methods A total of 150 cases of elderly NSCLC patients with cytological or pathological diagnosis were retrospectively reviwed. Doublet chemotherapy group was treated with platinum-based dual drugs，and single agent chemotherapy group was treated with the third generation chemotherapy drug monotherapy. Short term effect，progressionfree survival（PFS） and overall survival（OS） were observed. Results All the patients could be evaluated. In single agent chemotherapy group，PR in 6 cases（21.4％），SD in 2 cases（7.1％），PD in 20 cases（71.4％），and effective rate was 21.4％，while in doublet chemotherapy group were 48 cases（39.3％），10 cases（8.2％），64 cases（52.5％）and 39.3％. The effective rate of the two groups had no difference. The median PFS and OS was 5.0 months vs. 7.0 months（P=0617）and 7.4 months vs.10.7 months（P=0.473）in single agent chemotherapy group and doublet chemotherapy group, respectively. There were no statistical differences of survival between the two groups in ECOG scores，age and CCI 1-2. CCI 3-4 patients in doublet chemotherapy group had a better median PFS（3.5 months vs.8.3 months，P=0.001）and median OS（5.0 months vs. 8.3 months，P=0.019）than those in single agent chemotherapy group. The main side effects were neutropenia，anemia，thrombocytopenia and nausea／vomiting, which were almost in grade 1-2，and grade 3-4 toxicities in doublet chemotherapy group were more than those in single agent chemotherapy group. Conclusion Platinum-based dual drugs regimen has similar short-term and long-term effect to single agent regimen in elderly NSCLC patients. CCI 3-4 patients treated with platinum-based dual drugs has a better survival, but has more side effects.