A unknown function protein gene SikSD-82 was cloned from Saussurea involucrata Kar.et Kir.cDNA library under cold-stress.Physicochemical properties and molecular features of SikSD-82 were predicted by bioinformatic analysis showed that SikSD-82 gene encoding a stable protein with 262 amino acids,which contains a conserved Wali7(wheat aluminum induced protein) ,a member of Gn_AT_Ⅱ superfamily,had significant identity of 60.89% with stem-specific proteins from Ricinus communis.Phylogenetic analysis indicated that SikSD-82 protein was most closely related to Solanum lycopersicum stem specific protein.The subcellular localization of SikSD-82 was found mostly in the nucleus .Under aluminum stress,SikSD-82 transgenic plant accumulate less A1 and MDA concentration in roots than that of wild-type plants,and their roots are longer than that of wild-type plants’,which shows that SikSD-82 transgenic plants have more aluminum tolerance than that of wild-type plants.