We investigated the effect of the bone lengthening by callostasis on the anastomosed artery of tibia of rabbit. A pair of small external fixator were placed in the left tibiae of twelve rabbits.In eight rabbits, left posterior tibial arteries of were cut and anastomosed at the same location and level of osteotomy. Among them, in four rabbits, distraction began after latency period of 7 days at the rate of 0.5mm per day. At 3 weeks after 25 % lengthening, angiography was done for assuring patency of blood flow. The right and left posterior tibial arteries were prepared for Masson's trichrome and H & E staining to observe change of the vessel histologically. On angiography, all vessels were patent and there were no visible narrowings. Histologically, anastomosed sites were hyperplastic but any fibrosis was not observed through out the section. Compared to the untouched right posterior tibial arteries, the thickness of intima and media of the anastomosed and lengthened arteries was increased significantly(intima:5.18times(P<0.0001) and media 1.19times(P<0.001)), Compared to the lengthened only without anastomosis, and the anastomosed without lengthening, the thickness of intima was increased 3.31 times(P<0.001) and 2.14 times, respectively. This study observed that anastomosed arteries have kept their patency intact during lengthening with some physiologic response such as hyperplasia of intima and media. With the result of the study, in the case of bone shortening combined with the vessel damage, it can be clinically possible to begin distraction lengthening and to repair vessels simultaneously