Different stages of somatic embryos were obtained in embryogenic callus from embryogenic cell suspension culture of longan,and used these somatic embryos as the test material.The RT-PCR combined with RACE method was used to clone the complete cDNA sequences and DNA sequences of homeodomain transcription factor WUSCHEL(DlWUS) from embryogenic callus of Dimocarpus longan Lour..The complete cDNA sequence of DlWUS was 1 110 bp,encoding 285 amino acids DNA sequence analysis indicated that it contains 2 introns.DlWUS located in nucleus;it had no signal peptide,had transmembrane structure,homeobox domain,WUS box and EAR-like domain.Anglicizing phylogenetic tree of WUS in plants indicated that DlWUS and CsWUS belonged to the same branch,therefore,DlWUS belonged to WUS family.Real-time quantitative PCR results indicated that DlWUS had expression at all stages,but it expressed at the highest levels in the globular embryos,suggesting that DlWUS play a major role at longan somatic embryogenesis.In a certain concentration range,DlWUS showed up-regulated expression patterns under exogenous IAA and GA₃ and down-regulated expression patterns under exogenous SA.