Abstract: Objective : To investigate the relationship between the expression of Caspase-3 and DFF45 proteins and the clinicalpathological characteristics of pulmonary carcinoma. Methods : The Caspase-3 and DFF45 protein levels in 57 patients with pulmonary carcinoma were detected by means of immunohistochemistry and Western blot. Results : In 57 cases of pulmonary carcinoma, the positive rate of Caspase-3 and of DFF45 proteins was 66.67% and 29.82% respectively. The positive expression of Caspase-3 and DFF45 protein was not associated with the pathological types (P>0.05), but was highly associated with cellular differentiation degree and lymph node metastasis (P<0.05). In the 57 cases, a positive correlation was present between Caspase-3 and DFF45 protein expression (P=0.024). Conclusion : The down -regulation of Caspase-3 and DFF45 may contribute to tumor growth and lymph node metastasis in pulmonary carcinoma.