Despite modem diagnostic, staging, and therapeutic advances, esp. with molecular biologic techniques, the 5-year survival rate of all cases of lung cancer does not exceed 15%. With better understanding of tumor biology, one may improve survival through proper treatment. Here we present the clinical significance of several biologic markers as prognostic markers in patients with non-small cell lung cancers. The survival has correlated with the expressibility of proliferative cell nuclear antigen (PCNA), epidennal growth factor receptor (EGFR), p53 and/or blood group antigen A (BGAA) using immunohistochemistry in 46 cases patients with non-small cell lung cancers. The results were as follows: (1) The expression of BGAA was correlate with better survival in median survival and in 2-year survival and that of PCNA was correlated with worse survival in median survival and 2-year survival rate. (2) The expression of EGFR or p53 was not valuable to predict prognosis in non-small cell lung cancers. (3) With simultaneous applications of PCNA, EGFR and p53 immunostain, the patients with 2 or more negative expressions showed better prognosis than the patients with 2 or more positive expressions. In conclusion, it is suggested that the expression of blood group antigen may be a positive prognostic factor and that of PCNA may be a negative prognostic factor and also, the combination of expressions of PCNA, EGFR and p53 may be used as a negative prognostic factor.