We studied prognostic factors of survival in 121 patients unresectable non-small cell lung cancer treated between March 1983 and November 1988 at forth department of internal medicine, Kinki university school of medicine, about histology, clinical stage, age, sex, performance status, Brinkman Index, hemoglobin, serum TP, serum Alb, serum LDH, pulmonary function and chemotherapy. The prognostic factors were studied using survival rate by Kaplan-Meier method, univariate analysis by Log-rank test and generalized Wilcoxon test and multivariate analysis by proportional hazard model of Cox. The prognostic factors of pretreatment were age, serum Alb, serum LDH, pulmonary dysfunction of mixed type and performance status. In the classified study according to histology, age and pulmonary dysfunction of mixed type were prognostic importance in patients with squamous cell lung cancer. Hemoglobin in patients with squamous cell lung cancer was important, too. The chemotherapy given good response improved patient's prognosis.