Endoclita vietnamensis Buchsbaum & Grehan, a newly discovered pest of dried Eucalyptus, is a typical example of native insect adaptation to an alien host. Adult larvae scatter the eggs on the ground below the forest, and the larvae live in the litter layer to the third stage after hatching, and then transfer the damage to the tree. Even in mixed forests, larvae can accurately locate the host, which leads to be assumed that the olfactory system of larvae is conducive to host selection. In addition, the olfactory system also plays an important role in the mating process of adult worms. Here, we studied the transcriptome of the head, chest and abdomen of the 5th instar, 12th instar and antennal antennae of the adult, and investigated the expression profile of olfactory proteins. A total of 66 olfactory proteins were identified,14 of which were newly identified, including three odor-binding proteins (OBPs), four odor receptors (ORs), one taste receptor (GRs), and six ionic receptors (IRs). The expression profiles showed that all OBPs, ORs and GRs were expressed to varying degrees in the three stages, except OR22 and OR25 which were not expressed in the head of the 5th instar larvae. The expression level of EsigOR23 was the highest among all olfactory proteins, and was significantly high in the head of 5th instar larvae. The expression of EsigGOBP9 in adult antennae was significantly higher than that in adults at 5 and 12 ages. This study would provide a molecular basis for further study of the chemical sensation of the E. vietnamensis. EsigOR23 and EsigGOBP9 have unique expression patterns, which may be important proteins affecting host selection in larvae and courtship behavior in adults, respectively, and deserve further exploration.