Abstract: Two-year-old H.moellendorffii was used as the test material, and different periods of low-temperature treatments were given at its seedling stage 10,20 days and 30 days, respectively, with H.moellendorffii without low-temperature treatment at 5 °C as the control, and the effects of different time of seedling low temperature treatment on the process of bud differentiation and growth of the H.moellendorffii were investigated,in order to provide reference for slowing down the process of the development of the H.moellendorffii,increasing the time of nutrient growth,and improving the yield.The results showed that the low temperature treatment advanced the beginning of flower bud differentiation and all stages of flower bud differentiation in H.moellendorffii,and the longer the low temperature treatment time,the more significant the effect.The endogenous hormone content and carbon/nitrogen metabolism were significantly correlated with flower bud differentiation of H.moellendorffii,among which gibberellin,abscisic acid and soluble sugar content were positively correlated with flower bud differentiation,while growth hormone,zeatin,starch and soluble protein content were negatively correlated with flower bud differentiation of H.moellendorffii.