Abstract: To obtain the best condition for discoloration prevention of yam, Greenness yam being material, it was studied that citric acid, sodium D-ascorbate, extraction of oat and sulphite prevent yam discoloration. Based on the result of single factor influence. The optimum prescription for fermentation was selected by orthogonal experiment L9(33). It was seen that the best condition prevention of discoloration of yam were, citric acid 0.3%, sodium D-ascorbate 0.1% and marinated 45min.