In this study, we report molecular characterization and expression patterns of AmLEA5 (AAW31666.1) under abiotic stresses, a gene cloned from cold- and drought-stressed Ammopiptanthus mongolicus by a modified solid subtractive hybridization method. Bioinformatic analysis shows that the gene encodes a group 5 late embryogenesis abundant protein (LEA).The overall length of AmLEA5 is 693 bp, and the cDNA contains a 297 bp ORF encoding a polypeptide of 98 amino acids with a calculated molecular mass of 10.6 kDa. AmLEA5, with more phosphorylation sites, is a kind of hydrophilic protein. The analysis of codon bias shows that AmLEA5 gene is bias toward the synonymous codons with A and T at the third codon position. Phylogenetic analysis indicates that AmLEA5 protein is most closed to Medicago truncatula LEA (ACJ84182.1) in genetic relationship. qRT- PCR analysis indicates that AmLEA5 is up-regulated by cold, drought, salt and hot stresses. Specifically, transcription of AmLEA5 accumulated more at the late stage of cold treatment. Intracellular localization analysis shows that AmLEA5 proteins tagged with yellow fluorescent proteins (YFP) is more likely localized in the cytoplasm and nucleus. Our results suggest that AmLEA5 may plays important roles in abiotic stresses responses, especially in cold tolerant mechanism in A. Mongolicus.