Objective To investigate the effective route and proper method in transfecting gene into liver graft mediated by adeno-associated virus vector.Methods Three routes including hepatic artery,portal vein and hepatic artery+portal vein,and 3 methods,i.e.routine,circulation and clamping were employed for infusion.The best infusion route and method of gene transfection into liver graft were determined by observing the color change of liver and detecting liver function and transfoetion rate of liver cells.The safety of these methods was evaluated.Results In all the infusion procedures,the color of the liver grafts turned from red to white,no apparent color differenee of the livers and no enlargement nor mottling were observed under surgical microscope.The liver color was back to normal immediately after blood flow was restored.No significantly statistical differences of the ALT values were observed among all the groups(F=0.343,1.265,0.055,P＞0.05).Adeno-associated virus vectors coding for the enhanced green fluorescence protein(AAV2-EGFP)were successfully transfected into liver cells by the 3 infusion routes 1 week later,and the difierences of transfection rates via the 3 routes had no statistical significance(F=0.080,0.091,0.045,P＞0.05).The transfoction rate of AAV2-EGFP was the highest at any time points when using the clamping method,and then followed by circulation method and routine method,with statistical differenee(F=3.880,2.976,5.129,P＜0.05).The transfection rates of AAV2-EGFP were increased progressively and peaked at the 6th week,and then they were decreased gradually.Conclusions Infusion via hepatic artery is the effective route for gene transfection and clamping the vessels can elevate the transfection rate of AAV2-EGFP.All procedures were performed without detectable liver injury.The transfection of gene into liver graft mediated by adeno-associated virus vector is a slow and persistent process.