Objective To study the effect of recombinant growth hormone (rhGH) on improvement of liver function and liver regeneration in animal and patients after hepatectomy. Methods The liver cirrhosis model of SD species mouse was set up, then the mouse were randomly divided into experiment group and control group, then 30%-40% liver of all the models were resected, rhGH was used by hypodermic injection (0.2-0.4ml/100g) in experimental group, and the equal dose of N.S. were given in control group every day. Then liver function, arterial blood ketone body ratio(AKBR), and the regenerated liver/body weight ratio (RL/W) were determined, histopathology of the cirrhosis with microscope and electron microscope and the mitotic index (MI) of liver cell on 7, 14 and 28th day after operation were observed. Clinically,39 hepatectomized patients were randomly divided into experiment group and control group, liver function, PA， Glu, RI and AKBR were measured preoperatively and on 1, 7,14th day after operation. Postoperative clinical course were also compared between the two groups. Results In the animal experiment group, as compared with the control group, AKBR was obviously higher (P＜0.01), seruim level of total protein and PA were increased faster (P＜0.05), and RL/W was higher. The mitotic index of liver cell was increased faster on 14th day, the numbers of regenerated liver cell with double nucleus and rough endoplasmic reticulum were higher in 14 and 28th day. In the clinical experiment group, as compared with the control group, serum total bilirubin, alanine aminotransferase and aspartate aminotransferase were lower on 7 and 14th postoperative day (P＜0.05). Serum albumin, PA, Glu, RI and AKBR were higher on 7, 14th postoperative day (P＜0.05). Conclusion Both experimental and clinical study show that the rhGH can promote liver regeneration and improve liver function after hepatectomy.