Gamma amino butyric acid (GABA), known as a non-protein amino acid and major inhibitory neurotransmitter in the brain, has several functional properties such as neurotransmission, induction of hypotension, tranquilizer, and diuretic effects. The purpose of this study was to isolate and identify lactic acid bacteria, producing high GABA in fermented soy curd. Thirty-two strains of tofu-forming lactic acid bacteria were isolated from kimchi which a traditional Korean food fermented with many kind of microorganism. Among 32 strains, four strains (strain No. 10, 104, 214, 249) formed firm soycurd. In order to select lactic acid bacteria having high GABA producing potential, the isolated strains were cultured in the soymilk and fermented for 48 hr at 37℃. A strain No. 383, which showed highest GABA contents in fermented soycurd, was identified as L. sakei by 16S rDNA sequencing and API analysis, and named as L. sakei 383. L. sakei 383 showed optimal growth up to 24 hr at 35℃ in MRS broth. The optimal time and temperature for GABA production were 18 hr and 35°C in soymilk. In the optimal condition time and temperature, GABA content of fermented soycurd by L. sakei 383 was 8.65 mg/100 g.