Emerald ash borer (EAB) (Agrilus planipennis) is a beetle native to Asia. In recent years, EAB is expanding its range toward Europe, where European ash (Fraxinus excelsior) exists. EAB is a big threat to American Fraxinus species, but it is unclear how EAB will affect F. excelsior. In this study, we use whole transcriptome sequencing to examine transcriptomic response of four F. excelsior clones challenged by EAB. We established EAB infestation, harvested cambium from the infested are, prepared sequencing library with mRNA selection/TruSeq and sequenced using NovaSeq 6000 (2x100 bp).