Body color dimorphism is a common phenomenon in a wide range of insect taxa. In Gampsocleis sedakovii obscura (Walker), the two morphs are green and brown. In order to explore the variation within the same species with different body color phenotypes, morphology, genetics, and male calling songs were compared within Gampsocleis from Inner Mongolia, China. Recordings of the male calling songs were compared based on the acoustic variables including pulse duration, pulse interval, dominant frequency, highest frequency, and lowest frequency. This analysis was combined with sequencing of mitochondrial DNA cytochrome c oxidase subunit I and cytochrome c oxidase subunit II and examination of morphological traits to perform cluster analyses. The morphological and the mitochondrial genetic analyses revealed no differences between green and brown morphs, but the acoustic analysis showed completely different male calling between the morphs, thus suggesting that there is a connection between acoustic signals and body color dimorphism in G. s. obscura. These findings also revealed that the acoustic variation with body color dimorphism could provide evidence for insect acoustic signal divergence and the process of subspeciation, even speciation.