Objective: This experimental study was carried out to evaluate the effects of Saussurea Radix and Plantaginis Herba on cellular viability, proliferation, apoptosis and expression of the cell cycle-related genes in cultured gastric cancer cells. Method :MTT assay for analysis of cellular toxicity and the effect on suppression of cellular viability, $[^{3}H]$ thymidine incorporation assay for evaluation of the effect on suppression of DNA replication, tryphan blue exclusion assay for measurement of induction of apoptosis and Quantitative RT-PCR for analysis of the effects on expression of cell cycle or apoptosis-related genes were performed. Results: Antitumor activity of Saussurea Radix associated with inhibition of cell cycle progression and promotion of apoptosis caused by transcriptional regulation of p53, p21/Wafl and the other related genes was observed.