Abstract: In this paper,the effect of cooking time( 5,8,10,15 min) on physicochemical properties and sensory characteristics during the fermentation of soybean paste were explored according to the content of total nitrogen( except paste mash),amino acid nitrogen,water- soluble protein,as well as the hard of soybean and sensory score.Results showed that under the condition of different cooking time,all the indicators of content of total nitrogen,amino nitrogen,water- soluble protein increased significantly during the first period of fermentation( 1³0 d),thereafter with a slight change or maintain homeostasis. Meanwhile,all the indicators had significant differences( p < 0.05) because of the condition of different cooking times,especially for the paste mash. The hardness of soybean was significantly affected the cooking time and decreased with the longer of cooking time.The soybean of15 min sample was severely damaged. According to the sensory evaluation,the sample of cooking 8 min had higher score in color,aroma,taste and taste body.