Abstract: Three screened and mutagenesised species of moulds was selected as trial strains, and were cultured in soybeans. Aspergillus niger 3.4309 was used to do single factor test for its higher fibrinolytic activity, using fibrinolytic activity as index, determine its optimum fermentation temperature was 30℃, inoculation amount was10%, the ratio of water was 0.6mL/g, loading capacity was 20g/250mL, the optimum pH was 5.5. Under these optimum conditons, the fibrinolytic activity could reach 1.16 TAME U/mL. Then used the mixture design method to determin the optimum mixed inoculation amount was:Aspergillus niger 3.4309 4.3% added, Aspergillus oryzae 3.800 2.1% added and Aspergillus oryzae 3.6% added. In this way, the fibrinolytic activity could reach1.311 TAME U/mL, 13% higher than fibrinolytic activity of single mould fermentation.