Abstract: One pair of degenerate primer was designed according to the conservative domains of the pathogenesis-related protein PR1 genes of other plants and using RT-PCR and RACE technology，a full length cDNA of pathogenesis-related protein 1，named PsPR1，was obtained from leaves of Paeonia suffruticosa‘Luhehong’，treated by Cylindrocladium canadense. Sequence analysis indicated that PsPR1 consisted of 744 bp and the 5′ UTR and 3′ UTR were 42 bp and 225 bp，respectively. The length of open reading frame（ORF）was 477 nucleotides encoding 158 amino acids with molecular weight 14.8 kD，isoelectric point 6.19. The deduced amino acids possessed SCP_PR1_like conserved domain. The PsPR1 was highly homologous to PR1，which have been isolated from other plants. Real-time PCR analysis indicated that expression level of PsPR1 was the highest in sepal，but the lowest in leaves. PsPR1 was significantly induced by C. canadense and signaling molecule salicylic acid（SA）and expression level of PsPR1 reached the highest peak in 24 h and 12 h，respectively，which showed that PsPR1 might involved in the disease defense.

Key words: Paeonia suffruticosa, pathogenesis-related protein 1, gene clone, expression analysis