Abstract: In this study, process conditions of enhanced fermentation of soybean meal (non-sterilized) by Pediococcus pentosaceus NCU301 was optimized, and changes of nutrients and anti-nutritional factors in soybean meal were determined. According to the viable counts of lactic acid bacteria, optimum fermentation conditions were obtained through single factor experiment and response surface analysis of Box-Behnken. Results showed that the optimum fermentation time, temperature, and inoculum respectively were 50.0 h, 30.3℃, 8%, respectively, with the optimum ratio of material to water 1:0.82.Under these conditions, the viable bacteria amount of fermented soybean meal reach 1.15×10¹⁰ CFU/g. Moreover, the changes of nutrients and anti-nutritional factors before and after fermentation were determined. The results showed after enhanced fermentation, the content of crude protein, acid soluble protein, peptide and amino acids in soybean meal increased by 4.78%, 36.04%, 52.21%, 19.10%, respectively, while trypsin inhibitor activity and urease activity declined by 89.56% and 91.72%, comparing with soybean meal of unfermented. And the content of crude protein, and amino acids in soybean meal increased by 0.6%, 35.89%, while acid soluble protein, peptide, trypsin inhibitor activity and urease activity declined by 4.64%, 3.35%, 72.79% and 60%, comparing with soybean meal of natural fermented. Pediococcus pentosaceus as starter culture of soybean meal not only replaced of antibiotics, but also increased nutritive value of soybean meal.