【Aim】This study aims to examine the function of LdecOR30 in the Colorado potato beetle, Leptinotarsa decemlineata. To do so, the odorant receptor gene OR30 from the antennae was cloned to determine the expression levels of LdecOR30 in different tissue samples of male and female adults, and investigate its electrophysiological responses to the main alcohols in various odor molecules.【Method】On the basis of the full-length transcriptome and next-generation transcriptome re-sequencing data of L. decemlineata, the coding sequence (CDS) of LdecOR30 was cloned by PCR. Quantitative real-time PCR (qPCR) was employed to analyze the expression profiles of LdecOR30 in the antennae, head (without antennae), thorax, abdomen, legs, and wings. The electrophysiological responses of LdecOR30 to 16 alcohols were examined via the Drosophila empty neuron system combined with single sensillum recording. A Y-tube olfactometer was employed to test the effects of specifically responsive compounds on the behavior of L. decemlineata.【Result】The full-length cDNA sequence of LdecOR30 was successfully cloned. Sequence analysis indicated that this odorant receptor contained six transmembrane domains. qPCR results showed significantly higher expression of LdecOR30 in the antennae of both male and female adults than in other tissue samples. Single sensillum recordings in the Drosophila empty neuron system indicated that LdecOR30 responded to five alcohols, with an increase of over 20 spikes per second. Y-tube olfactometer assays demonstrated that cis-3-hexen-1-ol had a significant attractive effect on female beetles, with an attraction rate of 80%, while 1-octen-3-ol exhibited significant repellency of 70% to both male and female adults.【Conclusion】The odorant receptor gene LdecOR30 is highly expressed in the antennae of L. decemlineata adults, regardless of sex, and responds to five different alcohols, including cis-3-hexen-1-ol. These findings suggest that LdecOR30 plays an important role in the recognition and localization of host plants by L. decemlineata.