We induced arterial balloon injuries twice via a hyperdiastolic balloon catheter inserted into the carotid artery of Wister rats in order to observe the changes in the intima and the media. The thickness of the intima reached a maximum by 14 days after the injury. In a comparison of the thickness of the intima with samples having a once-induced arterial balloon injury, the samples with twice-induced arterial balloon injuries were found to have thickened more significantly. When the proliferating cells of the intima were observed, many proliferative smooth muscle cells were found. In the models of the twice-induced arterial balloon injuries, the area of the media decreased, while the area of the intima increased. In the models of the twice-induced arterial balloon injuries, intimal hyperplasia with positive remodeling1 was observed, and findings were obtained that were substantially similar to lesions due to either intimal hyperplasia of arteriosclerosis lesions or intimal hyperplasia of restenotic lesions after PTA or stent placement.