Antiproliferative activity of the ethanol extract of Atractylodes japonica rhizomes (AJEX) was investigated using methyl thiazolyl tetrazolium (MTT) assays with various cancer cell lines (HL-60, MCF-7, SK-Br-3, MDA-MB-453, HepG2, Hep3B, PC-3, LNCaP, MKN 28, MKN 45, and HT-29 cells). Gastric carcinoma cell lines were the most responsive in terms of cell proliferation. The $IC_{50}$ of MKN 28 and MKN 45 cells were 35.98 and 27.57 ${mu}g/mL$, respectively. Moreover, gastric carcinoma cells exposed to AJEX underwent apoptosis, as determined by Annexin V binding assay. Compared to respective control level, exposure to the AJEX at each $IC_{50}$ concentration resulted in a remarkable increase in the shift of cell populations. Present results suggest that AJEX possess potential anticancer properties.