Abstract: To study the clinical effect and toxicity of Erlotinib in the treatment of senile patients with advanced Non- small cell lung cancer(NSCLC). Methods Twelve senile patients with advanced NSCLC taken Erlotinib 150mg orally once a day. Valuations were made about curative effects,symptoms,quality of life, mean survival time, time to progression and toxic reactions. Results Total mitigative rate of the focus was 25.0%,total control rate was 66.7%, alleviative rate of clinical symptoms was 58.3% and the levels of CYFRA21-1 and CEA in the effective patients were significantly lower than those before the treatment(P<0. 01). Mean survival time of all the patients was 8.1 months. Time to progression was 4.2 months. Conclusion Erlotinib is an effective and tolerated molecular target medicine,it provides a safe and effective way for the treatment of senile advanced non-small cell lung cancer.