Abstract: Objective To compare the efficacy and toxicity of inductive chemotherapy with pemetrexed followed by radiotherapy for patients with lung adenocarcinoma.Methods Patients with stage Ⅲa/b or Ⅳ and histologically confirmed lung adenocarcinoma were evaluated from July 2008 to April 2012(n=95).Patients received inductive chemotherapy with pemetrexed or paclitaxel followed by thoracic radiotherapy or chemotherapy with pemetrexed alone,respectively.Primary end point was the tumor response rate(RR),progression-free survival(PFS),1-year survival rate and toxicity.Results Tumor RR were 83.3%,81.8%and 62.5% in three groups of inductive chemotherapy with pemetrexed or paclitaxel followed by thoracic radiotherapy or chemotherapy with pemetrexed alone,respectively.PFS was 12.0 months,10.9 months and 5.7 months.The 1-year survival rate was 80.0%,78.7%and 46.8%.Tumor RR and PFS were statistically superior in pemetrexed/radiotherapy versus pemetrexed alone,and toxicity was significantly lower than in paclitaxel/radiotherapy.Conclusion The treatment of pemetrexed/radiotherapy for lung adenocarcinoma could prolong the survival of patients.Compared with the treatment of paclitaxel/radiotherapy,pemetrexed/radiotherapy provides similar efficacy with better tolerability and more convenient administration.