An embodiment is a blood flow measurement device that generates blood flow information based on data collected by repeatedly scanning an interested cross section intersecting a blood vessel of an eye fundus using OCT. A data collector scans four or more cross sections intersecting the blood vessel. A first calculator determines a first gradient and second gradient of the blood vessel by analyzing a first data group and second data group among four or more pieces of data corresponding to the four or more cross sections collected by the data collector. A second calculator determines a gradient of the blood vessel at the interested cross section based on the first gradient and the second gradient. A blood flow information generator generates the blood flow information based on the gradient determined by the second calculator and the data collected by repeatedly scanning the interested cross section.
