Objective To investigate the role of pathologically increased-cyclic stretch in proliferation of vascular smooth muscle cells (VSMCs) during hypertension, and the effect of Forkhead box protein O1 (FOXO1) during this process. Methods Coarctation of abdominal aorta above kidney artery of rat was used as hypertensive animal model, and sham-operated animal as control. FX-4000 cyclic stretch loading system was used to apply 5% physiologically cyclic stretch and 15% pathologically cyclic stretch during hypertension on VSMCs in vitro. Western blot was used to reveal the expressions of FOXO1 and phosphor-FOXO1 in VSMCs, and BrdU kit to detect the proliferation of VSMCs in vitro. By using RNA interference in static, the role of FOXO1 on cell proliferation was further detected. Results After abdominal aorta coarctation for 2 and 4 weeks, respectively, the blood pressure was significantly increased compared with the sham operated rats. The proliferation of vascular cells in aorta of hypertensive rat was significantly increased, and so did the expressions of FOXO1 and phosphor-FOXO1. In vitro experiment revealed that 15% cyclic stretch remarkably increased the proliferation and expressions of FOXO1 and phospho FOXO1 in VSMCs. Target siRNA transfection in static decreased the expression of FOXO1 and phosphor-FOXO1, as well as the proliferation of VSMCs. Conclusions Pathologically increased-cyclic stretch may increase the expression and phosphorylation of FOXO1, subsequently modulate VSMC proliferation during hypertension. Based on animal models, this study intends to reveal the role of FOXO1 in vascular reconstruction of hypertension and the involved biomechanical mechanism, so as to make the mechanobiological mechanism of hypertension explicit and discover new target in the prevention and treatment of vascular remodeling.