Abstract: Plants of the genus Juglans, including Juglans regia, Juglans sigillata, and Juglans mandshurica, are widely-cultivated woody oil crops with significant economic value and positive ecological benefits. Studies reveals the Juglans genus exhibits significant allelopathic effects, which are crucial for understanding ways to adapt to the environment and their potential application in ecological restoration and the development of forest-fruit industry. This article reviews the allelopathic characteristics, the allelopathic substances, physiological mechanisms of leaves, leaf litter and green husks of J. regia, J. sigillata and J. mandshurica in the current research, with prospects for future studies in this field.