Abstract:Low lactose mare's milk was Studied in the paper by the method of enzymatic hydrolysis， lactose content was lower than 2.0 g/100 mL. Effects of different pretreatment methods on fresh mare's milk lactose hy－ drolysis rate and different sterilization methods and storage temperature on the sensory were studied，based on the optimum conditions of the lactase. Lactose content was lower than 2 g/100 mL and lactose hydrolysis rate 75 %， with lactase 2 000 NLU/L，pH=6.2，40 ℃，2 h. No significant precipitation and slight browning in the high temperature sterilization conditions. Normal temperature for storage was appropriate.