Fumigant toxicities of 20 plant essential oils, and fumigant and contact toxicities of the components of active oils and their analogues against adzuki bean weevil, Callosobruchus chinensis (L.) were investigated. Fumigant toxicity varied with plant essential oils and concentrations. The 24-h LC50 values against adult C. chinensis were 3.14, 6.68, 8.59, 8.90 and 10.23 mg/L air concentration for Gaultheria fragrantissima, Illicium verum, Croton anisatum, Aniba roseodora, and Bursea delpechiana, respectively. To elucidate structure-activity relationship of methyl salicylate (MS) and trans-anethole (tA), fumigant and contact toxicities of MS, methyl 3-hydroxybenzoate (M3HB), methyl 4-hydroxybenzoate (M4HB), methyl 2-methoxybenzoate (M2MB), methyl 2-acetoxysalicylate (M2AS), methyl benzoate (MB), salicylic acid (SA), trans-anethole (tA) and 1-methoxy-4-propylbenzene (PB) were investigated. The 24-h LC50 values of fumigant toxicity were 3.48, 5.36, 6.39 and 9.27 mg/L air concentration for MS, MB, tA and PB, respectively. The 24-h LD50 values (µg/beetle) of contact toxicity were 28.89, 33.27, 33.56, 44.81 56.31, 38.59 and 69.20 for MS, M2AB, M2MB, MB, SA, tA and PB, respectively. Structural differences were identified that may contribute to understanding the insecticidal activities of methyl salicylate and trans-anethole.