Abstract: Aiming at optimizing the process of condition of color protection for fresh cut potatoes,the effect of eight methods kinds of color protection methods on fresh-cut potato slices were compared in the view of sensory evaluation,browning intensity and polyphenol oxidase activity,and the color protection methods by L-cysteine were optimized by L₉(3⁴)orthogonal test,with sample thickness,concentration of L-cysteine,soaking time and storage temperature as factors. The results showed that L-cysteine was better than the other methods,and the optimized color protection process by L-cysteine were as followed,sample thickness of 3 mm,concentration of L-cysteine 0.4%,soaking time 45 min and stored at 4℃ after soaking. When processed by the optimized color protection process,fresh cut potatoes were uniform in yellow color without browning had sensory evaluation value of 93.00,browning intensity of 0.32,and polyphenol oxidase activity of 0.50 U/g.