Tropical plants, Vetiver (Vetiveria zizanoides) and Patchouly (Pogostemon cablin) are useful plants for fragrance industry and there are traditionally insect control plants in Indonesia and Philippines. Roots of vetiver and leaves of patchouly are known to be naturally resistant to insect attack. The ether extracts of root and leaves of there tropical plants have insect repellency against the yellow fever mosquito, the rice weevil and the azuki bean weevil. Both extracts were fractionated by column chromatography and analyzed GC-MS. Sesquiterpens, β-vetivone and vetiverol from the vetiver and patchouli alcohol from the patchouly were identified as the insect repellent substances against the yellow fever mosquito. Patchouli alcohol was also identified as repellent against the rice weevil.