A lipopeptide extract of Bacillus amyloliquefaciens BACY1 (BLE) was found to induce cell death in human oralsquamous cell carcinoma (OSCC) cell lines, SCC4 and SCC25, in this study. The results of MTT assay showedthat BLE inhibited OSCC cell proliferation in a dose-dependent manner. BLE was also effective in increasingthe sub-G1 phases. Furthermore, when membrane damage in SCC4 cells treated with BLE was monitored byLDH assay, release of LDH was significantly increased. The protein and mRNA levels of pro-apoptotic Bax, andcaspase-3 were up-regulated by BLE. Taken together, these results suggest that BLE induces apoptosis and theninhibits the cell proliferation of human OSCC cells.