Plant MAPK (mitogenactivated protein kinases) cascades play a crucial role in the process of hormone signal transduction, various stresses responses and plant growth and development.  The fulllength cDNA sequence of Akebia trifoliata mapk3 gene was amplified by using the technology of rapid amplification of cDNA ends (RACE) method.  Subsequently, characterization of Aktmapk3, including gene alignment, phylogenetic tree, conserved domain and protein structure were analyzed by bioinformatics, while the expression level of mapk3 in different tissues of Akebia trifoliata were analyzed by realtime quantitative PCR method.  Result showed that the Aktmapk3 gene contained an 1 164 bp open reading frame (ORF) which encodes 387 amino acids, and the coding protein contained an ATP binding site (IPR017441), MAPK conserved site (IPR003527), and Serine/threonineprotein kinase active site (IPR008271) suggesting that this protein might be activated by phosphorylation, and then phosphorylate downstream protein to executive physiologic function.  The result of Realtime PCR exhibited that Aktmapk3 was the highest abundance in bud, mature leaf and flower, suggested that Aktmapk3 might be involved in the development of bud and flower.