The rat globin gene system is suitable for studying a coordinated regulation of seven genes from two gene families. A rat reticulocyte cDNA globin library has been constructed and two clones analyzed in detail. pBRrg 5 contains alpha while pBRrg X contains beta type sequence. These cloned cDNAs will be useful probes of structure and function of rat globin genes. The deduced amino acid sequences extend the information about the variability of rat globin chains.