Context: Panax ginseng is well known for its various bioactivities, but specific knowledge on ginseng proteins (GPs) is limited. Aims: Protein components were extracted from ginseng and antitumor activity in human breast cancer cell line MCF-7 was investigated. Settings and Design: Five methods were applied to extract GP and the antitumor effects and mechanism of GP on MCF-7 were explored, including proliferation, cell cycle, apoptosis, and migration. Subjects and Methods: Five extraction methods were employed. MCF-7 cell proliferation was measured using a cell counting kit-8 with different GP concentrations (0, 0.25, 0.5, 1, 2, and 4 mg/mL) and half inhibitory concentration values were calculated. Cell cycle, morphology, and apoptosis were investigated using immunofluorescence staining and flow cytometry. Migration was probed by scratch wound healing and transwell assays. Quantitative-polymerase chain reaction and western blotting were performed to analyze apoptosis-associated gene/protein expression. Statistical Analysis: Experimental data were analyzed by Microsoft Excel and SPSS software. Results: Acetone extraction achieved the highest GP purity and yield. GP inhibited proliferation of MCF-7 in a time-dependent manner and induced cell cycle arrest at G1/S and apoptosis. Scratch wound healing and transwell assays showed that cell migration was also inhibited by GP and expression levels of Bcl-2 and Bax were affected. Conclusion: GP elicits antitumor activity by inhibiting cell proliferation and migration and inducing cell cycle arrest and apoptosis in MCF-7 cells and may act via the Bcl-2 and Bax apoptotic pathway.