To assess the insecticidal activity of extracts from Illicium verum against museum insect pest Demestes maculates, mortalities of its larvae and adults under different dose or treatment time were investigated by bioassay methods. Results showed that both extracts (anise oil and (E)-anethole) were highly toxic to both life stages (larvae and adults) of D. maculatus. Furthermore, the insecticidal activity was dependent upon both dose and exposure time. With the increasing of the dose level and the exposure time, higher mortality was obtained. On the other hand, results also indicated that D. maculatus adults were more tolerant against the extracts from I. verum than larvae. At the same time, it was interesting to demonstrate that the toxicity of anise oil was more effective than (E)-anethole against D. maculatus under the same experimental condition. The highest mortality 95% was achieved at 72 h with anise oil against larvae at a dose of 32/cm³. As naturally occurring insect-control agents, the I. verum extracts described could be useful for managing populations of museum pest D. maculates.