Harpiphorus, a monotypic genus of subfamily Allantinae (Symphyta: Tenthredinidae), was established based on Tenthredo (Emphytus) lepida Klug. The genus is close to Hemibeleses Takeuchi but can be easily distinguished by the following characteristics: the cell 1M in fore wing with a distinct petiole dorsally and cell M in hind wing closed. Harpiphorus is widely distributed in Europe, but has not yet been found in outside the continent. The larva of this genus is phytophagous attacking the oak species (Quercus trojana Webb and Q. robur L.). As a result of the present study, the genus Harpiphorus is reported based on H. lepidus for the first time from South Korea and the Eastern Palaearctic region. A diagnosis, figures of morphological features are provided.