Objective: To clone the rat augmentor of liver regeneration (AL R) cDNA and analyse its structure. Methods: The rat ALR cDNA was o btained by using RT-PCR method with total RNA extracted from the regenerating hepatic tissue,then was subcloned into the pGEM-T vector.The sequence of rat A LR cDNA was proved to be correct by sequencing.The rat ALR cDNA and its deduced amino acids sequence were both compared with Genebank database to analyse homol ogy. Results and Conclusion: There isn′t any mutation in cloned r at ALR cDNA.The rat ALR cDNA has higher homology with yeast ERV1 cDNA ,and their homology of DNA and protein is 54.99%and 47.01%respectively. We also find tha t a portion of the rat ALR protein has identity with the binding motif in zinc f inger proteins.