Abstract: The fumigation activity was determined against Sitophilus zeamais and Tribolium confusum with cuminaldehyde,cumin essential oil and microcapsules.Results showed that cumin essential oil at 20 μL / L reached100% corrected mortality after 12 h of fumigation. Cuminaldehyde had less effective than cumin essential oil.Microcapsules of cumin essential oil inhibited insect activity,however,less effective than cuminaldehyde.T.confusum showed more sensitivity to cumin essential oil at higher concentration,cuminaldehyde inhibited activity of S.zeamais obviously. The better effect of fumigation were gained along with the increase of concentration and fumigation time. It was suggested that active ingredients of cumin essential oil showed good fumigation effect against two insects through synergistic function.