 Methods: 50 patients undergoing elective intestinal tumor surgery were enrolled, ASAI-III, aged 18-65 years. After the induction of general anesthesia, cardiac indexCI, cardiac outputCO, stroke volume variabilitySVV, stroke volume indexSVI were monitored with Vigileo system, while pleth variability indexPVI and perfusion indexPI were monitored with Massion Radical 7 system. During the surgery, goal directed fluid therapy was conducted according to the data of CISVI and SVV. Heart rateHR, mean arterial pressureMAP, central venous pressureCVP, CO, CI, SVI, SVV, PI, PVI were recorded while after the induction of anesthesiaT1, making surgical incisionT2, performing intestinal anastomosisT3 and closing the abdominal incisionT4. And we calculate the correlation of SVV and PVI using Pearson Correlation Analysis at different time points. 