Abstract: Disclosed is use of 2-amino-3-methylhexanoic acid as a plant immunity inducer and in the preparation of a plant immunity inducer. The development of 2-amino-3-methylhexanoic acid as an active substance into a plant immunity inducer can be used for improving the resistance of plants to biotic and abiotic stresses, effectively stop the infection and reduce the pathogenic levels of fungi, viruses and bacteria on plants, and at the same time, significantly improve the tolerance of plants to high temperature, low temperature, drought and salt stress. 2-amino-3-methylhexanoic acid has the features of being safe, environmentally friendly, and highly efficient.