Abstract: The insecticidal, fumigation and repellent activities of the essential oil extracted from Ajania potaninii against Tribolium castaneum and Lasioderma serricorne adults were investigated. The results showed that the insecticidal activity of essential oil against T. castaneum and L. serricorne adults were median lethal dose(LD₅₀)=34.18 and 22.79 μg/adult, respectively; and the fumigation activity of A. potaninii oil against T. castaneum and L. serricorne adults were medican lethal concentration(LC₅₀)=34.21 and 41.05 mg/L, respectively. However, its toxicities were much weaker than that of Pyrethrin and Phosphine, which had the contact activity (LD₅₀=0.13 and 0.09 μg/adult) and fumigation activity (LC₅₀=0.17 and 0.08 mg/L) against the two insects, respectively. Meanwhile, A. potaninii essential oil exhibited obvious repellent activity against T. castaneum but little repellent activity against L. serricorne. The percentage repellency (PR) value of the essential oil against T. castaneum was more than 90% after 2 h and 4 h at the highest tested concentration of 78.63 nL/cm². Moreover, it showed similar repellent activity with the positive control of DEET at other lower test concentrations (15.73, 3.15, 0.63 and 0.13 nL/cm²). However, at the highest tested concentration of 78.63 nL/cm², the PR value of the essential oil against L. serricorne was close to 50% after 2 h and 4 h, which is significantly lower than DEET. In addition, the essential oil of A. potaninii was shown no repellent activity against L. serricorne at other lower test concentrations.