A plant stress tolerance-inducing agent is provided that contains, as an active ingredient, a compound having a specific quinone skeleton. Alternatively, a plant stress tolerance-inducing agent is provided that contains, as an active ingredient, at least one compound selected from the group consisting of 1,4-naphthoquinone, 5-hydroxy-1,4-naphthoquinone, 5,8-dihydroxy-1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, 5-hydroxy-2-methyl-1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone, 2,3-dichloro-5-nitro-1,4-naphthoquinone, 2,3-dichloro-6-nitro-1,4-naphthoquinone, 2-methoxy-1,4-naphthoquinone, 2-amino-3-chloro-1,4-naphthoquinone, a shikonin compound, and an alkannin compound.