Abstract: The enzyme active center of S2 and its stability under the conditions of different ambience,temperature and pH value were analyzed,it is found that the activity of S2 enzyme preparation varies with metal ions,Ca2+and Co2+accelerates its activity evidently,quite in favor of enzymatic degumming,however,Cu2+and Zn2+heavy-metal ions show high depression effects on the activity;its stability at different pH value and temperature is varied greatly and exhibits best when pH value is 8.5,temperature is 55℃.