Abstract: The infrared and Raman spectra of the long chain mono-unsaturated fatty alcohol estersas insect sex pheromones of lepidoptera have been reported. The assignments of the vibra-tional frequencies of the compounds have been made. The spectral differences among to taleleven compounds at room temperature (liquid state) and lower than freezing point(solid state)temperature have been investigated. The relationships between some characte-ristic bands and the chain structures of the compounds have been obtained. Combining with some physical constants, these relationships can be used to estimate the double bond posi-tion and chain length of the compounds.

Key words: Mono-unsaturated alcohol ester, Infrared spectra, Rainan spectra, Sex pheromone