Objective To study the function of the genes regulating sex determination and differentiation during liver regeneration at transcriptional level. Methods The genes regulating sex determination and differentiation were obtained by referring to the theses and collecting the data of databases at NCBI, GENMAPP, KEGG, BIOCARTA and RGD, and their function and expression changes in rat liver regeneration were analysized by the Rat Genome 230 20 array. Results The initial and total expressed gene numbers in the starting phase of liver regeneration ［half to four hours after partial hepatectomy (PH)］, G0/G1 transition (4 to 6 hours after PH), cell proliferation 6 to 66 hours after PH), cell differentiation and tissue structural function reconstruction (72 to 160 hours after PH) were 41,6,18,3 and 41,25,57,41 respectively, which showed that the related genes were mainly triggered in the starting phase, and worked in different phases. Their expression similarity was classified into 5 groups:only up, predominantly up, only down predominantly down, up/downregulation, involving 22,9,15,9 and 7 genes respectively, and the total frequencies of their up and downregulation expressions were 231 and 146 respectively, demonstrating that the expression of the major genes was increased, and the minority decreased. Their expression time relevance was classified into 15 groups, showing that the cellular physiological and biochemical activities were phase related during liver regeneration. The gene expression patterns were classified into 20 types, indicating the diversity and complexity of the cellular physiological and biochemical activity. Conclusion The genes regulating male determination, male and female differentiation are enhanced mainly in the late early phase and prophase of liver regenera