A novel late embryogenesis abundant (LEA) gene (AY804193), named CbLEA, has now been isolated from Chorispora bungeana. This rare alpine subnival plant can survive sudden snowstorms and low temperatures. The full-length CbLEA is 842 bp, with an open reading frame encoding 169 amino acids. The putative molecular weight of CbLEA protein is 17.9 kDa, with an estimated pI of 6.45. To investigate the functioning of this CbLEA protein in cold-stress tolerance, CbLEA was introduced into tobacco under the control of the CaMV35S promoter. Second-generation ($R_1$) transgenic tobacco plants exhibited significantly increased tolerance to cold. These transgenics maintained lower malondialdehyde (MDA) contents and electrolyte leakage (EL) but their relative water content (RWC) was significantly higher compared with non-transgenic plants under chilling stress. Further experimental results showed that non-transgenic plants had severe freezing damage after exposure to $-2^{circ}C$ for 1 h, whereas the transgenics suffered only slight injury under the same conditions. Moreover, survival was longer in the latter genotype at that temperature. The extent of increased cold tolerance was positive correlated with the level of CbLEA protein accumulation, and was also reflected by the delayed development of damage symptoms. This indicates that CbLEA is an excellent stress tolerance gene, and holds considerable potential as a new molecular tool for engineering improved plant genetics.