Abstract: Under the condition of the weak acidity and normal temperature, the red pigment of the red-skin-radish is extracted and its properties are studied to determine the influence of the light, heat, oxidizer, reducing agent, pH value and such common metal ions as Fe3+, Fe2+, Cu2+, Al3+, Ca2+ etc. on the property of the pigment. Such pigment remains a good stability for the light and the heat, and is suitable for the food dyeing agent which is sterilized in high temperature. And this kind of pigment has great practicalp rospects.

Key words: the red-skin-radish, the red pigment, the property