The dyeing properties of chrysophanol on polyester (PET) were investigated. Chrysopahnol was stable with the pH range of 3 to 7. And in this pH range, the hue of Chrysophanol of dyed polyester showed very little change. The K/S values increased significantly when the temperature was raised from 90°C to 110°C, and if the temperature was 110°C, the dyeing time exceeded 90min, the dye uptake didn’t increase any more. The adsorption of chrysophanol on polyester accorded with Nerst Partition Relation, and the adsorption capacity increased linearly with the increasing chrysophanol concentration. The partition coefficient and affinity increased with the temperature rising.