WRKY transcription factor plays a vital role in response to cold stress in plants. To reveal the function of WRKY gene in Prunus mume,the PmWRKY40 gene was cloned from P. mume ‘Xuemei’ by RTPCR. The fulllength cDNA sequence of PmWRKY40 was 1 072 bp,containing a complete open reading frame (ORF) of 972 bp encoding 323 amino acids. The deduced amino acid sequence alignment of PmWRKY40 contained a conserved WRKY domain and C2H2 zincfinger structure. The results of phylogenetic analyses showed that the PmWRKY40 was most closely related to WRKY protein from P. avium. The results of quantitative PCR showed that PmWRKY40 was induced by cold and H2O2 stresses,but the induction levels of the gene expression were different between cold and H2O2 stress. Meanwhile,PmWRKY4 was significantly triggered by SA treatment and its expression was inhibited by ABA. It is indicated that PmWRKY40 from P. mume may play a key role in response to cold stress.