Objective To investigate the hepatocyte growth and differentiation during rat liver regeneration (LR) at transcriptional level. Methods The related genes were obtained by online data collection and literature review, and the gene expressions in rat regenerating liver were checked by Rat Genome 230 2.0 array. The relativity of the LR-related genes was identified by comparing discrepancies in gene expression changes between partial hepatectomy (PH) group and sham operation (SO) group. Results One hundred and ten genes were found to be related with liver regeneration. The initial and total expressing gene numbers occurring in the initiation phase of liver regeneration (0.5-4 hours after PH), G0/G1 transition (4-6 hours after PH), cell proliferation (6-66 hours after PH), cell differentiation and structurefunction reconstruction (72-168 hours after PH) were 63, 11, 43, 3 and 63, 43, 101, 80 respectively, indicating that the related genes were mainly triggered during the initiation phase, and worked at different phases. The total frequencies of their up and downregulation expression were 488 and 248, respectively, demonstrating that the expression of the major genes increased, and that of the minority decreased. Their expression profiles were classified into 6 types, displaying that the activities mentioned above were diverse and complicated during liver regeneration. Conclusion Hepatocyte growth and different