Objective To establish a model of transplanting neonatal cardiomycytes into the wall of rat inferior vena cava. Methods Neonatal cardiomyocytes (n=6, 5×106cells each, A group) or medium (n=6, B group) only were transplanted into the wall of inferior vena cava in female Fisher rats. At 21 days after transplantation, the contraction of transplanted cardiomyocytes was assessed and the inferior vena cava was processed for histology. Results Distinct rhythmic beating of the vena cava at the site of cell transplantation before and after the aorties were clamped (at a rate 141± 47 rpm and 88± 44 rpm which was dramaticly lower than aortic beating, with a statistical difference at P value of 0.03). Cardiomyocyte was seen in 6 rats who had neonatal cardiomyocyte transplantation, but not in 6 rats receiving media. Hematoxylin and eosin staining showed viable cardiomyocytes in the wall of the vena cava in 6 rats treated with neonatal cardiomyocytes, but not in 6 rats receiving media. Conclusion This study shows that neonatal cardiomyocytes can survive, mature and spontaneously and rhythmically contract after they are transplanted in the wall of inferior vena cava.