Soybean,wheat,meal,flour and wheat brans with different ratios were used to ferment four soy sauce koji,and the protease activity、amylase activity,β-glucosidase activity and the total phenolic content of the four soy sauce koji were measured respectively.Then the four soy sauce koji and the raw materials were assayed through these methods: DPPH radicals,ABTS + radicals and reducing power.The results revealed that Koji with ratio of soy: wheat flour: wheat bran = 4∶ 0.8∶ 0.2 had the highest DPPH radical scavenging capacity.Koji with ratio of raw materials for soy: wheat flour = 4∶ 1 had the highest ABTS + radical scavenging capacity,reducing power and the highest content of total phenolic.After solid fermentation of Aspergillus oryzae,DPPH radical scavenging capacity increased by 10 times,ABTS + radical scavenging capacity by 5 times,reducing power by 4 times and the content of total phenolic increased by 3 times.Soy sauce koji fermented with the soybean possessed stronger anti-oxidant activity than meal,and adding wheat brans could help improve DPPH radical scavenging capacity of the koji.