Since it was established that the alteration in gene expression occur during cold acclimation, a major goal in cold acclimation research has been to identify cold-responsive genes and to determine whether they play roles in freezing tolerance. Many cold-regulated genes (COR) were isolated and characterized in Arabidopsis and other cold tolerant plant species. Studies on regulation of COR in Arabidopsis have resulted in the discovery of a family of transcriptional activators, of which, CBF1, a member of the gene family, controls expression of a battery of COR in Arabidopsis and other cold tolerant plant species. During recent years, CBF-like genes were found in the genomes of chilling-sensitive plant species such as tomato and maize. Over-expression of Arabidopsis CBF1 confers elevated tolerance to chilling and drought stresses in transgenic tomato. These results promote our effort to identify and characterize CBF-like genes to improve tolerance of chilling-sensitive plant species to chilling and drought stresses.