Abstract: By-product of “blanching treatment" during mung bean sprouts processing was processed into clarified mung bean coat beverage.Color-protecting technology was improved based on the protective mechanism of chlorophyll in mung bean coat.After choosing the feasible color fixatives by single factor experiments, the best combination of color fixatives and the processing method were determined by orthogonal design experiments.Results indicated that the best process was initial extraction temperature of 80℃ and extraction time of 20 min, color fixatives (citrate sodium 0.20%, iso-ascorbyl sodium 0.016%, sodium tripolyphosphate 0.05%) under the conditions of pH 7.76.Natural yellowish green color of the water extract could still be maintained after sterilizing at 121℃ for 20min.Extracting and color-protecting process had little effect on the mung bean vigour to process mung bean sprouts.