Abstract: Objective 　To observe the effect and toxicity of gemcitabine plus carboplatin ( GC) and gemcitabine plus cisplatin ( GP) in patients with advanced non-small cell lung cancer (NSCLC) . Methods 　One hundred and fifty seven patients with histological confirmed NSCLC were enrolled in the study randomly.Twenty-one day for a cycle. Each case was evaluated af ter two cycles. Results 　Sixty patients to GC and 50 patient s to GP the objective response rate (CR + PR) was 53. 3 % vs. 55. 8 % in the GC and GP as first-line treatment . Fwenty-one patient s to GC and 24 patients to GP the objective response rate (CR +PR) was 26. 3 % vs 29. 6 % in the GC and GP as second2line t reatment . The median time to progression was 6. 4 months vs 7. 0 months in the GC and GP as first-line treatment and was 4. 8 months vs 5. 1 months in the GC and GP as second-line treatment arm respectively. The median survival time was 8. 9 moths vs 9. 3 moths and 12year survival was 29. 3 % vs. 32. 7 % in the GC and GP group respectively. No significant difference between arms was observed. The clinical benefit rate was 80. 3 % vs 64. 5 % in the GC and GP arm respectively. There was significantly difference between arms ( P < 0. 05) . There was no difference between the arms with hematological toxicity. GP group had a remarkably higher incidence of grade 3～4 nausea/ vomiting than GC group ( P < 0. 005) . Conclusion 　GC and GP group provided high effectiveness and safe. However, GC group provided a better overall tolerability and better clinical benefit with GP arm.