Abstract: This text is in the illumination to its Rubia Cordifolia L. pigment, temperature, dissolving, acid sealing, the characteristics in many aspects, such as food additive, etc. have carried on systemic research.The result shows: Rubia Cordifolia L. pigment apt to dissolve on water and have strong one acidproof and alkaline able to bear personning who reduce , able to bear personning who oxidize and able to bear all.