This study was carried out to detennine lactic acid bacteria (LAB) having bacteriocin producing ability from tofu sour liquid and brewer's grains media. A total of 16 LAB strains was isolated and screened for bacteriocin production. There were 13 strains performing their antimicrobial activities and of which, 4 strains were able to produce bacteriocin. Strain Lactobacillus DC213A was remarked with the significantly highest antibacterial activity based on bacteriocin zone diameters (22mm). Effects of conditions for bacteriocin production by Lactobacillus DC213A, such as inoculation level, incubation time, incubation temperature and culture medium, were also examined. The significantly highest levels of biomass and protein at 0.4 g/l00 ml and 778.55 ug/ml, respectively, were obtained in conditions as below: inoculation level 7 log cells/ml, incubation temperature 35°C, incubation time 3 days, a medium of tofu sour liquid added with 10 percent brewer's grains, 1 percent peptone and 1 percent beef extract. These levels of biomass and protein had no significant difference to compared with the results in the treatment of using the control MRS medium (De Man, Rogosa and Sharpe).