The Rb tumor suppressor gene performs a critical role in controlling cell proliferation and tumorigenesis; it recruits HDAC1 protein into the E2F complexes to repress transcription. In this study, we demonstrate that SNIP1, RB and HDAC1 were significantly expressed in same lung cancer tissues in a tissue microarray (TMA) containing 300 non-small cell lung cancers (NSCLC). High expression level of SNIP1 in tumor patients was significantly correlated with poor prognosis in NSCLC (log-rank P for OS=0.01, log-rank P for DFS=0.001). Functionally, SNIP1 competes with HDAC1 for binding to RB and reduces HDAC activity in vitro. Knockdown of SNIP1 reduced colony formation ability of lung cancer cells. These findings may indicate the involvement of SNIP1 in progression of lung cancer by regulating the RB/HDAC1 interaction.