Abstract: As a favorite garden flower, the tree peony lacks in comprehensive processing technology by now. Consequently the physical and chemical properties of peony red pigment were investigated, which must be foundmental theory for keeping fresh and the colors of peonys during storage, in addition, it will be helpful to extract red pigment from peonys. The properties of the peony red pigment extracted from "Luoyanghong" were studied. Results show that the red pigment has good water-solubility and is stable to light and heat in acid environment, but sensitive to the pH value of environment, oxidizer and reducer. The maximum adsorption wavelength for the pigment is 526.5 nm under pH<3. The influences of Zn²⁺, Mg²⁺, Fe²⁺, K⁺, Cu²⁺, Ca²⁺ are not obvious, but Sn²⁺ and Fe³⁺ can change the color of the pigment and increase the destruction.