Abstract: A total of 19 Hemerocallis cultivars of 5 different color systems were chosen as experimental materials, and determined CIELab via colorimeter and flavonoids via HPLC in petal limb, in order to reveal the differences of the main color substances among different daylily cultivars.The results showed that, yellow varieties had the highest L^* and b^*,at the same time, purple cultivars had the lowest L^* and b^*.However, red cultivars had the highest a^* but lower value of L^* and b^*,respectively.The main flavonoids were cyanidin derivatives, quercetin derivatives, isorhamnetin 3-rutoside and rutin.The relative contents of quercetin derivatives, isorhamnetin 3-rutoside and rutin in yellow and pink varieties were relatively higher than others; meanwhile the relative contents of cyanidin 3,5-glucoside, cyanidin 3-rutinoside, quercetin 7-glucoside and quercetin 3-arabinoside in orange, red and purple varieties were relatively higher.In conclusion, it showed significant difference in aspect of L^*,a^* and b^* among different varieties; the yellow and pink varieties had the higher relative content flavonoids such as quercetin derivatives, isorhamnetin 3-rutoside and rutin, however, the main flavonoids in orange, red and purple varieties were cyanidin derivatives and quercetin derivatives.