Indocyanine green (ICG) fluorescence angiography has recently been reported useful as a method for predicting intestinal blood flow and may reduce anastomotic leakage. However, the quantification method for ICG fluorescence angiography has not been established. We usually measure the tissue oxygen saturation (StO2 ) in the intestinal tract via near-infrared spectroscopy, as it is able to measure the oxygen concentration accurately and immediately shows objective data. In this study, we propose that the time to reach the anastomotic site after intravenous ICG injection is an effective parameter for quantifying ICG fluorescence angiography from the comparison to the data of StO2 in the intestinal tract.