Objective: To study the correlationship between the Slp2 gene expression and the prognosis evaluation of lung cancer. Methods: Total RNAs were extracted from 52 patients with lung cancer, and in four lung cancer cell lines (A549, GLC-82, NCI-H446, NCI-H460), Slp2 gene expressions were detected at mRNA level by reverse transcription-polymerase chain reaction (RT-PCR). Results: Up-regulation of the Slp2 gene was shown in 29 of the 52 (63.0%) lung cancer patients and all of the lung cancer cell lines, especially in younger patients (89.5% vs 44.4%, P<0.01 ), poorly differentiated lung cancer patients (81.0% vs 48.0%, P<0.05), mediastinum lymphonodus metastasis (77.3% vs 20%, P<0.05) and the patients with IIIa-stage lung cancer (73.1% vs 0, P<0.05). Conclusions: The expression of Slp2 gene is significantly higher in the tissue of lung cancer than in the normal controls, and is closely correlated with differentiation of the lung cancer tissue and the fact whether or not the metastasis of mediastinal lymph node occurs, as well as clinical staging, etc.