Abstract: Objective To observe the effect of small interfering RNA (siRNA)-induced MA PK p42 silencing on the survival of HeLa cells. Methods Two siRNAs targeting at the MA PK p42 gene and one random siRNA were synthesized respectively by Silencer?siRNA Construction Kit and transfected into HeLa cells by Lipofectamin?2000. The expression of p42MAPK in the transfected HeLa cells was analyzed by Western blotting and immunohistochemistry, and the morphology of cells were observed with electron microscope. TUNEL assay and Annsxin V/PI staining were employed for detecting the cell apoptosis. Results The expression of p42MAPK in the HeLa cells was remarkably suppressed after transfection with the two siRNAs, reduced by about 2.5 and 3.2 folds respectively in comparison with the negative control. Chromatin margination in the cell nuclei were observed in the transfected cells, and TUNEL assay and Annexin V/PI staining further confirmed the occurrence of cell apoptosis. Conclusion In vitro MAPK p42 siRNA-1 and siRNA-2 transfection can specifically silence the gene expression and induce apoptosis of HeLa cells.