Abstract：This paper studies the effect of vermicompost substrate formulated with different nitrogen dosages on tomato（Lycopersicon esculetum Mill.）seedling development, with an aim to understand the role of vermicompost in raising strong seedling in greenhouse vegetable production. The results indicate that all tested items of tomato seedlings raised in vermicompost substrate are obviously better than those in commercial substrate（CK）. During the early and middle stages of seedling development adding urea 0.5 kg·m-3 is good for plant height, stem diameter, leaf expanding and leaf numbers. If adding urea 1.0 kg·m-3 during these stages, the chlorophyll content, stem diameter and leaf number are the highest. If adding urea 2.0 kg·m-3 during these stages the leaf numbers, leaf expanding degree and plant height are the highest. During the middle stage, if adding urea 0.5 kg·m-3, the root length is the longest. While adding urea 2.0 kg·m-3, the root surface area, root diameter and root volume are the highest. Therefore, in raising tomato seedling, vermicompost substrate can replace the traditional substrate. During the early and middle stages of tomato seedling development, adding urea 0.5 kg·m-3 has good effect. While at the late stage adding urea 2.0 kg·m-3 can gradually promote tomato seedling growth. The optimum amount of urea added to vermicompost substrate for tomato seedling development is 0.5 kg·m-3.
