Flo-Trac/Vigileo system is developed by Edwards Technology, and monitors the continuous cardiac output via peripheral arteries. The monitoring approaches of this system prove to be convenient, safe and minimally invasive. As an important indicator of the system, stroke volume variation (SVV) can accurately reflect the volume status of patients. The principle of SVV is the preload change, which is caused by the intrathoracic pressure changes between inspiratory and expiratory phases, will lead to arterial pulse pressure fluctuations, thus affecting stroke volume (SV). SV may vary under different volume loads. Through measuring and analyzing these differences and then assessing the circulation status, SVV provides guidance for fluid therapy. The continuous and real-time SVV monitoring can provide data of patients' circulation status, thereby optimizing clinical fluid treatment options and avoiding excessive or insufficient volume. For patients with gastrointestinal surgery, SVV guidance during the surgery can accurately regulate fluid infusion, which will contribute to the early postoperative recovery and improve patient prognosis.