Objective. To investigate the counter-effect of intermittent artificial gravity, the present study examined vasoreactivity changes of femoral and mesenteric arteries in rats subjected to simulated weightlessness plus standing or centrifugation. Method. Forty male Sprague-Dawley rats were divided into simultaneous control (CON), simulated weightlessness (SUS), simulated weightlessness plus 1 h standing (STD1), simulated weightlessness plus 1.5 G centrifugation (1.5 G), and simulated weightlessness plus 2.6 G centrifugation (2.6 G) groups. Responses of arteries to vasoconstrictor were examined in vitro using isolated femoral and mesenteric arterial rings. Result. The contractile responsiveness to KCl or PE of femoral and mesenteric arterial rings isolated from SUS significantly decreased as compared with CON. And those of STD1 and the two centrifuged groups significantly enhanced as compared with that of SUS. Whereas there was no difference among STD1, 1.5 G, 2.6 G and CON. Conclusion. Simulated weightlessness may result in decreased contractile responses to KCl and PE of rat femoral and mesenteric arteries. Both STD1, 1.5 G, and 2.6 G prevented the decrease of contractile response to KCl and PE of femoral arteries.