Abstract: Objective 　The current study was designed to investigate the relationship between the expression of caspase-3, PARP and DFF45 proteins and the clinicalpathological characteristic of non-small cell lung cancer (NSCLC) . Methods 　Levels of caspase-3, PARP and DFF45 protein in 87 patient s with NSCLC were detected by the second generation immunohistochemical Elivision methods and Western blot . Results 　In 87 NSCLC patients. The rates of caspase-3, PARP and DFF45 proteins positive was 66. 67 %, 33. 33 %, 29. 88 %, respectively. The positive expression of caspase23 and DFF45 protein were not associated with the pathological types ( P > 0. 05), but was highly associated with cellular differentiation degree and lymph node metastasis ( P < 0. 05) . But PARP expression was only associated with lymph node metastasis ( P = 0. 014) . In 87 NSCLC, a negative correlation were present between caspase-3 and PARP protein expression ( P = 0. 000), a positive correlation was present between caspase23 and DFF45 protein expression ( P = 0. 020) . Conclusion 　Caspase-3 obviously inhibit s invasion and metastasis of pulmonary carcinoma by extensively degrading target proteins such as PARP. The down-regulation of caspase-3 and DFF45 may cont ribute to tumor growth and lymph node metastasis in pulmonary carcinoma by making the pulmonary carcinoma cell more resistant to apoptosis.