In order to study the effect of UBAP1 gene on UBAP1 down-regulated nasopharyngeal carcinoma (NPC) cell line HNE1, the pcDNA3.1(+)/UBAP1 mammalian expression recombination was constructed and transfected into HNE1 cells. G418 was used to obtain the neomycin-resistant transformants of which indicated the vector was present in the HNE1 cells. The expression of UBAP1 gene was detected by RT-PCR and dot blot. The cytobiologic characterizations of the transfected HNE1 cells were probed by population double time (PDT), xenograft of nude mice and cell cycle analysis. The results showed that the PDT of HNE1 cells with expression of UBAP1 was longer than that of vector transfected HNE1 cells and untrasfected HNE1cells, and the most UBAP1 transfected cells went into phase G0-G1 compared with the two other cells. It also presented inhibiting the tumor formation in nude mice. Thus, these data suggested that UBAP1 gene plays an important role in the cell growth of HNE1, and might be a good candidate for tumor suppressor gene correlated with NPC.