Korean Oak Wilt (KOW), was first recorded in Gyeonggi Province in 2004, and since then has increased steadily in its occurrence and ecological and economic impacts. Platypus koryoensis vectors the symbiotic fungus Raffaelea quercus-mongolicae, which is the causative agent of KOW. KOW may be closely related to recent climate changes, which have allowed P. koryoensis to extend its distribution range in Korea. And it results in greater overlap with the susceptible host tree, Quercus mongolica throughout Korea. In this regard, changes in the climate suitability of P. koryoensis and Q. mongolica were predicted using CLIMEX model and the influences of other environmental factors such as elevation and the number of days with heat wave were also identified in this study.