PROBLEM TO BE SOLVED: To provide a bacterial wilt disease resistant inducer which contains a compound indicating resistant induction activity against a bacterial wilt disease as an effective component, and a bacterial wilt disease prevention method using the compound.SOLUTION: The bacterial wilt disease resistant inducer contains an L-body amino acid as an effective component. The bacterial wilt disease can be prevented by making an objective plant such as tomato absorb the L-body amino acid. In particular, it is preferable that the l-body amino acid is at least one selected from a group composed of L-histidine, L-arginine, L-lysine, L-aspartic acid, L-glycine, L-cysteine, L-phenylalanine, L-proline, L-alanine, L-glutamine and L-methionine.
