The present research was achieved to study the toxicity of fixed oils of clove buds (Syzygium aromaticum) and spearmint leaves( Mentha spicata) against larvae and adults of Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) and the adults of the drugstore beetle, Stegobium paniceum (L.) byusing a new fumigant technique. Germination test was conducted in order to assess the effect of tested oils at the highest concentration on wheat seeds after 24 hrs. A GC/MS analysis was performed to record the main chemical constituents in tested oils. Analysis of the toxicity data showed that, clove fixed oil exhibited the strongest fumigant toxicity against all tested insects. T.granarium larvae showed a very high resistance against both oils comparing with adults. Germination test showed no adverse effect of the tested oils on wheat seeds germination comparing with control. The GC chromatogram of clove buds fixed oil showed that, the main constituents were eugenol (37.43%) eugenol acetate (11.47%), caryophellene (10.44 %), linoleic acid (9.42%) and caryophellene oxide (8.58%). The GC-MS chromatogram of spearmint fixed oil showed that, the main constituents were carvone (33.9%) and limonene (2.7%).