Abstract: Objective To establish a 6-10B cell line with stable expression of KIAA1173 gene and study the biological behaviors of the cells. Methods The total RNA was extracted from normal skeletal muscular tissues for cloning of KIAA1173 gene by means of RT-PCR which was subsequently introduced into pcDNA3.1 (+) vector. The recombinant eukaryotic expression vector pcDNA 3.1(+)-KIAA1173 was constructed and identified by endonuclease digestion and sequencing before transfection into 6-10B cells via lipofectamine with the empty vector as the control. The positive cell clones were obtained by G418 selection. Stable expression of KIAA1173 gene in the transfected 6-10B cells was determined by RT-PCR, in situ hybridization and immunocytochemistry, and the biological behaviors of the transfected cells were observed by MTT assay, cell invasion assay and tumorigenesis assay in nude mice. Results High expression of KIAA1173 at both mRNA and protein levels was observed in the transfected 6-10B cells. The capability of proliferation, invasion and tumorgenicity of the KIAA1173- transfected cells in nude mice was lowered in comparison with those of the cells transfected with pcDNA3.1 (+) vector (P<0.05). Conclusions KIAA1173 genes may function as a potential tumor suppressor of nasopharyngeal carcinoma both in vitro and in vivo. The 6-10B cell line expressing KIAA1173 has been obtained, which can be helpful for further study of KIAA1173 gene.