Abstract: The effects of 4 kinds of metal ions and 4 kinds of food additives were investigated on the stability of anthocyanins pigment from purpule sweetpotato in this paper. The results showed that K+ , Zn2+, Mg2+ and Cu2+ showed significant color-enhancing effect and could increase the stability of PSPA.Both of glucose and sucrose had the color-protecting capability and potassium sorbate showed no adverse effect on the PSPA.Ascorbic acid showed remarkably degradation effect of PSPA, which absorbance value decreased by 39% under the temperature at 50 ℃ for 3h when the concentration of ascoric acid was 0.25mg /mL.