Objective: To investigate the rule of allicin induced apoptosis.Methods: Terminal deoxylnucleotide transferase directed X-UTP nick and end labelling (TUNEL) assay, DNA gel electrophoresis and light microscopy were used to observe apoptosis. Results: Trypan Blue staining positive rates of OVCA-3 cell were under 18.5%after being exposed to allicin at t he d osage 0.01-100 μg/ml for 2 h and 10 μg/ml for different time. Allicin induced apoptosis of OVCA-3 cells at 1-100 μg/ml for 2 h. Apoptosis peak was shown at 50 μg/ml. Apoptotic cells accounted for 65.9%of the population. Conclusion: Allicin of appropriate dosage induces apoptosis of OVCA-3 cel l, while has little toxicity on OVCA-3 cell. That is important for clinical app lication of allicin.