[Objectives]This paper was to investigate the effect of exogenous 24-epibrassinolide on nitrogen metabolism of cucumber seedlings under hypoxia stress. [Methods]A hypoxia-sensitive cucumber genotype( Cucumis sativus‘Zhongnong 6') was used and we investigated the effect of EBR on activity of key enzymes involved in nitrogen assimilation of plants under hypoxia. [Results]Total N content of leaves was decreased remarkably under hypoxia while EBR restored it to the control level. NO-3content was increased in le...