Abstract: The paper is based on a research of the inflorescence of Tagetes erecta L. The experiment studies also include the preliminary study of effects of light, heat, pHvalue, reductant, oxide, sucrose, preservative and metal ion on the stability of pigment. It proves that pigment is poor in resistance against light, heat and reductant. And it can endure oxide to some extent. The pigment can be applied to pHvalue widely. It is also found in the experiments that sucrose, preservative and metal ions such as Na⁺、K⁺ do not basically exert negative effect on the stability of the pigment while other ions such as Fe²⁺、Sn²⁺、Zn²⁺ have faintly negative effects on the chroma, and the increasement of ions such as Cu²⁺、Ca²⁺ have changed the color of solution of pigment and influenced on the chroma of pigment.