Background and objective With development of modern medicine, eliminating patients’ pain and mental disorder and improving the quality of life has become an important problem in patients with cancer. The aim of this study is to observe the impact of chemotherapy on quality of life and influencing factor of quality of life among lung cancer patients. Methods Sixty-one lung cancer patients were assessed with clinical outcomes and the EORTC QLQ-C30 questionnaires before chemotherapy, one week after 2 cycles of chemotherapy, one week after 4 cycles of chemotherapy. Results After 2 cycles of chemotherapy, effective rate was 40.0%. Social function decreased. Nause and vomiting, insomnia and appetite loss deteriorated (P<0.05). After 4 cycles of chemotherapy, effective rate was 23%. But after chemotherapy, physical, role, emotional, social function decreased; Appetite loss, nausea and vomiting, insomnia deteriorated, economics became difficult to some patients (P<0.05). In our study, we find female patients had more fatigue and appetite loss than male patients (P<0.05). Patients of low level of education had more fatigue and insomnia than patients of high level of education (P<0.05). Elder patients had more fatigue, appetite loss, nausea and vomiting than middle-aged patients (P<0.05). Grouped according to body mass index, the difference wasn’t statistically significant (P>0.05). Grouped according to the plasma albumin level, the difference wasn’t statistically significant (P>0.05). In hypoproteinemia group, symptoms and economic difficulties score was higher; High protein group, function and general health scores was higher. Conclusion After the chemotherapy, patients’ the lesion of cancer became smaller and clinical symptoms relieved, but some patients, fatigue, appetite loss, nausea and vomiting symptom deteriorated, emotion became bad. Quality of life of lung cancer patients decrease. We should pay more attention to the adverse reactions of chemotherapy and cope with them, give positive psychological intervention and improve patients, nutrition to improve the quality of life.