The genus Phymatodes Mulsant (Coleoptera: Cerambycidae) distributes throughout the Holarctic region. Approximately 50 species have been recorded from the world, and four species have been recorded in Korea. In 2010 and 2011, we collected many grape twigs which were severely damaged by unknown larvae of longhorn beetles from Gyeonggi province. They were reared at indoor condition until their emergences in order to see which species inflicted damage on the grape vines. Two species of unknown longhorn beetles were collected. They were identified as Phymatodes jiangi Wang et Zheng and P. zemlinae Plavilstshikov et Anufriev that are new to Korea. The diagnosis and illustrations of P. jiangi and P. zemlinae are provided.