Sensilla on the aedeagi of 4 species under the genus Damaster were studied using scanning electron microscopy. A total of 37 types of sensilla were distinguished from the aedeagi of the species examined. The number of sensilla types was the largest in D. (Coptolabrus) smaragdinus branickii, 25, and 23 in D. (C.) jankowskii jankowskii. In D. (Acoptolabrus) gehinii gehinii and D. (Damaster) blaptoides blaptoides, 22 and 21 types of sensilla were found, respectively. External morphology and distribution patterns of sensilla were also described. The phylogenetic relationships among the species were discussed based on their distribution patterns.