JNU-DY-6 was isolated from soybean meal and identified as Lactobacillus plantarum.It had great potential in acid production and it grew rapidly.we analyzed the composition of organic acids in fermented soybean meal by high performance liquid chromatography(HPLC).The results showed that there were 6 kinds of organic acids in fermented soybean meal,mainly including lactic acid,acetic acid,propionic acidandcitric acid.And the addition of molasses had great influence on the composition and yield ofpropionic acidin soybean meal.we worked out the optimum mass ratio for soybean meal fermentation(100 g) :Alcalase 0.5%,molasses 3%,the total organic acids content reached 14.643 g/L,which was 1.231 fold higher than that of normal contro lgroup respectively.By SDS-PAGE we found that soybean protein degraded into small molecular peptides.