Abstract: Physico chemical properties and extraction conditions of the red pigment in flowers of Bombax malabaricum were investigated. Results showed that good yield of pigment could be obtained by acid extraction, such as 0.1 mol/L HCl 50% C₂H₅OH(1:1)at 60℃ for 2h.The B. malabaricum red pigment is classified to anthocyanins, for which pH had significant effect on the tone of pigment. The pigment is stable to heat under acid condition. Under sunlight, degradation of the pigment could be accelerated, but regardless of ultraviolet light. Metallic ions Na⁺,Mg²⁺,Ca²⁺,Al³⁺,Cu²⁺,Pb²⁺ and Zn²⁺ had no effect on the tone of pigment, but Fe³⁺ and Sn²⁺ had severe disadvantageous effect. This kind of pigment possesses poor anti-oxidation ability. Addition of glucose, sucrose had no effect on the pigment.

Key words: Bombax malabaricum, pigment, extraction, physico chemical property