In this paper, a full-length cDNA-encoding cytosolic nicotinamide adenine dinucleotide phosphatedependent isocitrate dehydrogenase was isolated from maize and named ZmICDH. Analysis of the deduced protein sequence revealed that this gene had considerably high homologies with other plant ICDH genes such as those from rice, Arabidopsis and poplar. The gene was transcribed in all tissues tested, with the highest amount of transcript in root. Subcellular localization results indicated that ZmICDH was localized in cytosol. In an attempt to further understand the role of ZmICDH in maize, the functional characterization of the gene was conducted. The results indicated that the expression of ZmICDH was induced by drought and salt stresses. ZmICDH enhanced salt tolerance in transgenic Arabidopsis.