Abstract: Objective To explore the expression and biological significance of cPLA2 and Cox-2 in lung cancer tissues. Methods The expression of cPLA2 and COX-2 in mRNA level in cancerous tissue and tumor-adjacent tissue were detected by RT-PCR， while the immunohistochemical SP method was used to evaluate the expression of cPLA2 and COX-2 proteins in the corresponding tissues. Results The mRNA level of COX-2 and cPLA2 significantly increased (P<0.05)in lung cancer group as compared with those in the tumor-adjacent tissue.The positive expression rate of cPLA2 in cancerous tissue was 76.7%（46/60），but no expression was observed in tumor-adjacent tissue.The positive expression rate of cPLA2 in lung cancer was independent of clinic pathological parameters including size of tumor，histological type，TNM staging，histological grade and lymph node metastasis (P<0.05).The positive expression rate of COX-2 protein in cancerous tissue and tumor-adjacent tissue were 73.3%（44/60）and 13.3%（8/60）（P<0.01）.The positive expression rate of cox-2 protein in lung cancer was independent of size of tumor and histological type（P>0.05），but correlated with histological grade ，lymph node metastasis and TNM staging.The positive expression rate of COX-2 protein increased gradually with lymph node metastasis，the decrease of histological grade and the increase of TNM staging.There was a significant difference（P<0.05）. Conclusion It suggested that the expression of cPLA2 and COX-2 in lung cancer may play an important role in the process of carcinogenesis，and might provide a clinical basis for the early diagnosis and targeted therapy of lung cancer.