Abstract: In order to select the optimal fertilization period for cultivating high-quality, high-yield, and efficient Eucalyptus robusta medium and small diameter timber forests in the hilly areas of southeastern hilly region, different fertilization period treatment groups were set up in newly constructed forests, and standard plots were set up in each treatment group. Five fertilization period treatments were designed, with treatment 1 fertilizing for 1 year, treatment 2: continuous fertilization for 2 years, treatment 3: continuous fertilization for 3 years, treatment 4: continuous fertilization for 4 years, treatment 5: continuous fertilization for 5 years. After the experiment, the order of average tree height, average diameter at breast height, and average individual volume growth of each experimental plot is 5＞4＞3＞2＞1. The average tree height, average DBH and average tree volume of Eucalyptus robusta were the best after 5 years of continuous fertilization.