PROBLEM TO BE SOLVED: To provide a pulse wave propagation speed calculation system, a pulse wave propagation speed calculation method, and a pulse wave propagation speed calculation program which calculate a pulse wave propagation speed from an image.SOLUTION: The pulse wave propagation speed calculation system 1: acquires an image divides the image detects, for each of the blocks into which the image is divided, a biological reaction from a luminance signal in the block classifies, by living body, biological regions, each comprising one or more blocks in which a biological reaction is detected identifies the site of a biological region from the luminance signal in the biological region between a plurality of biological regions classified into the same living body and calculates a pulse wave propagation speed from the time difference of luminance signals obtained between identified sites.SELECTED DRAWING: Figure 1
