Twenty three isolates of bacteria, yeasts and molds were tested for their capabilities of producing proteolytic and amylolytic enzymes in the soybeen fermentation. However, only 3 isolates namely Bacillus subtilis B. 73, Endomycopsis fibuligera S.B.5 and Aspergillus oryzae W215 were found to have higher capabilities. Using any single culture or a mixed culture of these 3 isolates was also compared for their capabilities which found that a mixed culture gave better result i.e, producing 29.1 % soluble protein and 1.19 % reducing sugar after 30 hours of fermentation. Addition of 5 % rice flour did not give better result. In one experiment, using a 12 centimeter thick layer of seed gave 30.7 % soluble protein after 18 hours. In an improved cooking method, by adding water into a soaked soybean seeds before being steamed, gave best result, i.e, 31.3 % soluble protein after 24 hours. Hulled soybean seeds were not better than unhulled seeds by the mixed culture. A 4-centimeters thick layer of seeds fermented in a koji chamber using mixed culture gave better result i.e, 29.0 % soluble protein after 24 hours compared to any other thickness. A most suitable method of soybean fermentation intended for animal feed production gave 20.2 % soluble protein, 46.9 % true protein and 0.87 % reducing suger. The fermented soybean was tested with early weaned pigs and the data were analysed statistically found that there had been no difference in growth rate and feed conversion between the two group of pige when one group was fed with a mixed feed plus skimmed milk and the other was fed with mixed feed plus fermented soybean.