Proteinase inhibitors are one group of small proteins associated with the resistance of plants.We cloned two protease inhibitor genes(SmPI1 and SmPI2) from Salvia miltiorrhiza,and then analyzed the sequence characterizations using the bioinformatics methods and their expression patterns by real-time qPCR.The result shows that the completed ORFs of SmPI1 and SmPI2 are 222 bp and 216 bp in length,encoding 73 and 71 amino acids,respectively.SmPI1 and SmPI2 may be located in cytoplasm without transmembrane domain and signal peptide by prediction using bioinformatics methods.Amino acid sequences of SmPI1 and SmPI2 showed high homology to proteinase inhibitors from Morus notabilis,Theobroma cacao and Medicago truncatula.Quantitative PCR analysis showed that the expression of SmPI1 and SmPI2 were significantly induced under the treatment of methyl jasmonate(MeJA) or Xanthomonas campestris pv.Campestris(XC).This indicated that the protease inhibitor gene SmPI1 and SmPI2 could response to this two stress signals,and may be closely related to the resistance of S.miltiorrhiza.