Aim To investigate the effect of all trans retin oi c acid (ATRA) on reendothelialization and neointima formation in the rat's abdom inal artery after bal loon withdrawal injury. Methods The rat denuded ab dominal artery model with ba lloon withdrawal injury was performed. Twelve wistar rats were randomly assigne d to control group (intraperitoneal injection of 1 mL/d intralipid) and ATRA g roup [intraperitoneal injection of 4 μg/(g·d) ATRA] dissolved in intralipi d. After fourteen days balloon withdrawal injury in the situ perfusion fixa tion was performed with 10% formalin and the specimens were obtained. Histologi c observations and morphometric analysis were made. Results Reendothelialization area of arterial balloon injury increased in ATRA g roup compared with that in control group, while Neointima area is smaller in ATR A group than in c ontrol group. Conclusion ATRA has accelerated reendothelia lization and inhibited neointima formation of injuried vessels.