Abstract: The low-lactose yogurt and common yogurt were compared and analyzed in fermentation curve, post-acidification, yoghurts viscosity, viable cell numbers, and the main flavors compounds of acetaldehyde, diacetyl which stored at 4℃ in shelf life. The results showed that the low-lactose yogurt had quicker fermentation speed, weaker post-acidification. The viscosity, viable cell numbers and flavor compounds of acetaldehyde, diacetyl were also had a certain enhanced compared with common yogurt.