Abstract: Sex pheromone communication plays a major role in the courtship and mating of moths. Here, mechanisms of sex pheromone reception and encoding in male Helicoverpa assulta (Lepidoptera: Noctuidae) were reviewed. The antennal triochoid sensilla of male H. assulta receive the stimulations of sex pheromone cis-9-hexadecenal and cis-11-hexadecenal, as well as interspecific signal cis-9-tetradecenal. The three signals are detected by olfactory receptor neurons housing in the triochoid sensilla and transmitted to 3 distinct units of the macroglomerular complex. The associated projection neurons of the glomerulus of macroglomerular complex project the signals to higher olfactory centers, the mushroom body calyx and the lateral horn. Within the lateral horn, the pheromone sensitive projection neurons target the medial part, while the interspecific signal sensitive projection neurons target the lateral part. In this way, the sex pheromones in H. assulta are encoded in the mode of labeled-line at both the periphery and central levels, with different sex pheromone constituents being detected by corresponding sensory neurons and these different signals being transmitted directly to corresponding areas in the olfactory centers of brain.