For a better understanding of stress responses of Saussurea involucrata Kar.et Kir.,we reported molecular characterization and expression analysis of SiLEA14 gene from the S.involucrata Kar.et Kir.EST data under cold-stress.Sequence analysis showed that the cDNA of SiLEA14 contained a 468 bp ORF encoding a polypeptide of 155 amio acids.NCBI conserved domains analysis showed that SiLEA14 protein was a member of late embryogenesis abundant protein class 2.Phylogenetic analysis indicated that SiLEA14 protein was most closely related to Bupleurum chinense LEA-2 protein.Real-time quantitative PCR analysis showed that SiLEA14 was constitutively expressed,up-regulated by cold,salt and drought stress quickly.Subcellular localization assay indicated the SiLEA14-GFP fusion prortein was located in the nucleus.A overexpression vector was constructed,and transgenic tobacco plants transformed by Agrobacterium tumefaciens were obtained.Transgenic plants resistances to freezing and salinity were investigated.The gene function was analyzed via measuring the physiological stress indicators under different osmotic pressures.The results showed SiLEA14 gene can improve tobacco resistance to freezing and salinity.