RELATED TO AP2.12 (RAP2.12) is one of the Ethylene Response Factors (ERF) transcription factor and plays a key role in controlling plant root bending and responding to multiple abiotic stresses including hypoxia stress. In this study, FmRAP2.12 gene was isolated and characterized from Fraxinus mandshurica Rupr. The open reading frame (ORF) of FmRAP2.12 was 1170 bp and encoded a protein of 389 amino acids. The conserved domains, three-dimensional phylogenetic relationship of FmRAP2.12 was also investigated. Quantitative real-time (qRT-PCR) analyzed the expression of FmRAP2.12 in different tissues. The expression level of FmRAP2.12 was highest in roots followed by leaves, and lowest in male flowers. Abiotic stress and hormone signal-induced expression was established using qRT-PCR. Salt stress induced FmRAP2.12 to a double peak patt: the first peak value was at 6 h and the second at 72 h. Drought stress also induced FmRAP2.12 to a double peak patt: the first at 6 h and the second at 48 h. FmRAP2.12 was up-regulated after initiation of gibberellic acid (GA3) treatment, with a one peak patt at 24 h. FmRAP2.12 may not respond to cold stress and Abscisic acid (ABA) treatment. The tran-sient overexpression of FmRAP2.12 caused the up-ex-pression of downstream key genes of abiotic stress response and gibberellin pathway. Our research reveals the molecular characteristic and expression patts under abiotic stress and hormone condition of FmRAP2.12, pro-viding support for the genetic improvement of F. mand-shurica at a molecular level.