Abstract: In order to improve the quality of low fat yogurt,the effects of supplementing tremella polysaccharides(0.37,0.74,1.11,1.48,1.85 mg/mL)on microbe numbers,fermentation time and quality of low fat yogurt were investigated. The results showed that the numbers of Lactobacillus bulgaricus and Streptococcus thermophilus were increased gradually and the fermentation time was decreased significantly(p<0.05)in yogurt with the increasing of tremella polysaccharide concentrations. When the concentration of tremella polysaccharide were 0.37 and 0.74 mg/mL,the sensory characteristics of yogurts was best. Moreover,the water holding capacity,hardness and frangibility of yogurts were increased(p<0.05)when the concentration of tremella polysaccharides was 0.37 mg/mL. These data suggested that addition of proper amount(0.37 mg/mL)of tremella polysaccharides could increase the number of fermentation bacteria,promote fermentation and improve the water holding capacity,textural and sensory quality of the low fat yogurt,which could broaden the application range of the tremella polysaccharides.