Abstract: Objective：To construct the interfering effects of ALDH1A1 expression in HeLa cells with shRNA transfection，and next to explore the relationship between ALDH1A1 and the biological characteristics of HeLa cells. Methods：HeLa cells line were cultured in vitro. To determine the best screening concentration with different concentration of G418 solution. ALDH1A1 interfering of shRNA（including ALDH1A1-1719，ALDH1A1-574，ALDH1A1-740，ALDH1A1-921，and one of them has the best effective） and negative control recombinant plasmids（shNC） were transfected into human cervical HeLa cells line using Lipofectamine 2000 reagent. All of the ratio of shRNA to Lipo were 0.2 μg:1 μL，and the blank control group was only plused with Lipo 2000. The medium was changed after 6 hours，and observing the results of transfection under fluorescent microscope after 24 hours. Results：The best screening concentration of G418 was 400 mg/L，and five kinds of recombinant plasmids were successfully transfected into HeLa cells. And the transfection effective of ALDH1A1-1719，ALDH1A1-574，ALDH1A1-740，ALDH1A1-921，shNC were 4.67%，1.16%，12.45%，3.42%，1.02%，respectively. Conclusions：The shRNA of interfering ALDH1A1 expression transfection to HeLa cells was feasible and the effect was good.

Key words: ALDH1A1, RNA, small interfering, Transfection, HeLa cells