This study was proposed to adaptable species according to climate change using warmth index(WI) in Cheonan-Si. RCP 8.5 was used to estimate change of warmth index(WI) depending on climate change in Cheonan-Si. Climatic change of Cheonan-Si was estimated to change from cool temperate forest central zone to warm temperate forest zone. The following plant species will survive within WI change of Cheonan-Si from 2010 to 2050 : 18 species in the tree layer including Quercus serrata, Q. variabilis, Pinus densiflora, Q. acutissima etc.; 28 species in the shrub layer including Rhus trichocarpa, Lindera obtusiloba, Zanthoxylum schinifolium etc.; 24 species in the herb layer including Oplismenus undulatifolius, Carex lanceolata, etc.; 12 species in the vine plants including Smilax china, Cocculus trilobus, etc.