Objective：To investigate expressions of programmed cell death 5（PDCD5） in non-small cell lung cancer（NSCLC） and to explore its role in NSCLC occurrence and development. Methods：Cancer tissue and adjacent cancer tissue samples of 56 patients with NSCLC who received thoracic surgery and pathology confirmation from July 2011 to December in the first affiliated hospital of Nan－chang University were collected. Expressions of PDCD5 protein and mRNA were evaluated by immunohistochemistry and real-time PCR in NSCLC and adjacent cancer tissues. Results：Immunohistochemical results showed that PDCD5 positive expression rate was significantly higher in adjacent cancer tissues than in NSCLC tissues（ χ2=16.406，P=0.000）. PDCD5 positive expression rate was closely related with smoking，tumor differentiation，tumor TNM stage and lymph node metastasis，with statistically significant differ－ences. PDCD5 positive expression rate was decreased with the decline of smoking and differentiation degree and the elevation of TNM staging and lymph node metastasis；meanwhile，intensity of staining was also weaken. Real-time PCR results showed that PDCD5 mRNA relative expression was 0.397±0.266 in NSCLC tissues and 0.807±0.126 in adjacent tissues with statistically significant dif－ferences（t=10.795，P=0.000）. Conclusions：Expressions PDCD5 protein and mRNA are down-regulated，which may play an inhibitory role in NSCLC occurrence and development.