Abstract: Objective To observe the clinical effect of gemcitabine,cisplatin and gefitinib in combination in the treatment of advanced non-small cell lung cancer and its effects on serum neuron-specific enolase(NSE)and cytokeratin 19 fragment antigen 21-1(CYFRA21-1). Methods A total of 68 patients with advanced non-small cell lung cancer were selected as study objects. According to the different treatment methods, they were divided into control group and study group, with 34 cases in each group. The control group was treated with gemcitabine and cisplatin for chemotherapy, and the study group was treated with gemcitabine, cisplatin and gefitinib in combination for chemotherapy. The clinical efficacy, changes of serum NSE and CYFRA21-1 levels before and after treatment, and adverse reactions were compared between the two groups. Results Before treatment, there were no significant differences in serum NSE and CYFRA21-1 levels between the two groups(P>0.05); after treatment, the serum NSE and CYFRA21-1 levels of both groups were significantly lower than before treatment(P<0.05), and were significantly lower in the study group than the control group(P<0.05). There was no significant difference in disease control rate between the two groups after treatment(P>0.05). The total response rate of the study group was significantly higher than that of the control group(67.65%versus 41.18%, P<0.05). The incidence rates of thrombocytopenia and - leukopenia in the study group was 17.65%and 29.41%respectively, which were significantly lower than 41.18%and 55.88%in the control group(P<0.05). Conclusion Gemcitabine, cisplatin and gefitinib in combination has better clinical efficacy, which can significantly decrease the serum NSE and CYFRA21-1 levels, reduce the occurrence of adverse reactions and improve the prognosis of patients.