Abstract: Abstract: Seedlings establishment is one of critical periods in plant growth and development, and it is largely affected by environmental factors and hormonal regulation. As an important signaling molecules, Ethylene participates in and regulates the growth and development of seedling root according to numerous studies and the regulation mechanism of Ethylene affecting in plant growth and development has been a research hotspot in recent years. We summarize the research achievements about Ethylene biosynthesis and production pathway in recent decades. And we expound a series of physiological effects produced by Ethylene affecting in seedling root growth and development such as primary root elongation growth, lateral root and adventitious root initiation, stress resistance and adaptability of seedling root, aerenchyma formation etc. Furthermore, we analyze the signal function of ethylene, the interaction between ethylene and other signal molecules as well as Ethylene regulation to related genes in process of root growth and development. On the base of these studies, the further research problems of Ethylene in terms of production practice, physiological action mechanism and molecular regulation mechanism are put forward, thus these could be useful for people to reasonable utilize the technology of ethylene regulation.