Abstract: To explore the stress response and regulatory mechanism of NAC transcription factor family members in Populus euphratica,the promoter sequence of PeNAC121 gene was cloned from leaves of Populus euphrachiae by PCR and its structural characteristics were analyzed using bioinformatics tools. The PeNAC121 promoter was used to drive the expression of the GUS reporter gene in the triploid Populus tomentosa,and then GUS staining and enzyme activity quantitative analysis were performed in the obtained transgenic plants after different stress treatments. The cloned promoter sequence of PeNAC121 gene was 1 997 bp（located in the upstream of start codon ATG）in length,included a large number of light-responsive elements,and also contained a number of abiotic stress and phytohormone responsive elements,such as low temperature response element LTR,drought response element MBS,abscisic acid（ABA）response element,as well as gibberellin（GA）response elements,respectively. The result of tissue expression pattern showed that the PeNAC121 gene was mainly expressed in stems of P. euphratica,with low expression in roots and leaves. The results of GUS histochemical staining and enzyme activity test of transgenic plants showed that the PeNAC121 promoter was significantly induced by NaCl,mannitol,ABA and 4 ℃ low temperature respectively. It was speculated from the above results that PeNAC121 gene was closely related to the response to stress. The results showed that the promoter of PeNAC121 gene was an inducible promoter responding to multiple stresses. The study provid a theoretical reference for elucidating the role of PeNAC121 gene in stress response and regulation of P. euphratica.