Abstract: The changes of the physicochemical properties of fermented yak meat sausage before and after fermentation, including the pH value, Aw value, TBARs, nitrite and free amino acid content, as well as color and shear force, were measured among four temperatures of 25, 30, 35 and 40℃, in order to evaluate the effects of constant fermentation temperatures on the physicochemical properties of fermented yak meat sausage. The results showed that different fermentation temperatures had a significant effect on the physicochemical properties of the sausages (p<0.05). Higher fermentation temperature lowered the Aw and lightness value L^* after fermentation, increased TBARs content, redness a^* value and shear force. When the fermentation temperature was 35℃, the pH value was the lowest after fermentation and the change rate of nitrite content was the largest. Fermentation under 30℃ or 35℃ showed lower contents of total free amino acid.Based on the changes of physicochemical properties before and after the fermentation, fermentation at 35℃ may be the optimal for production of fermented yak meat sausage.