Corn by-product raw materials are then collected in that moisture is 12.6%, 44% of cellulose, lignin content 11.2% is pretty good raw material for making substrate for lactic acid fermentation. The process of hydrolysis of corn by-product is conducted by H2SO4 15%, at 121 0C, during the 90 minutes, collecting the relatively high glucose content of 3.7% (g/100 ml), for lactic fermentation. In the type 2 strain of bacteria introduced into selected research, L. casei and L. plantarum, L. plantarum is best suited for lactic fermentation because the strain has a pH of fermentation environment MRS = 4.25 lower strain L. Casei have pH= 4.75. Strain L. plantarum also for lactic acid concentration is 12.83 g/l higher payroll function that lactic acid strain L. casei obtained is 11.64 g/l. Upset after hydrolysis process could not be reused by for the low hydrolysis. Determine the optimal technology factors for lactic acid fermentation at the same rate of 6%, 5% glucose concentration, pH=6, temperature 38 oC, while lactic acid concentration obtained after 84 h is 19.07 g/l. When conducting tests of purified lactic acid from fermented fluids with the specifications that are referenced from the pilot study, the result of lactic acid purification is 51.81 g/l.