Abstract:Natto is a traditional fermented soybean product with high nutritional value，healthy function and more.It is not easy to be acceptted because of its special ammonia flavor all the time，so we need to improve the traditional natto flavor.In this experiment，a certain proportion of Phaseolus angularis was added to the traditional natto raw materials.Based on the comprehensive evaluation of sensory evaluation and nattokinase activity，the optimal fermentation conditions of Phaseolus angularis natto was studied by single factor test and orthogonal test.The optimum fermentation conditions were as follows：the fermentation temperature was 38℃，the fermentation time was 22 h，the mass ratio of Phaseolus angularis to soybean was 1 ∶4，and the activity of nattokinase was up to 942 U/g，which provided the theoretical basis for the development of diversified natto product and natto food.