This invention measures cerebral blood volume changes to evaluate, from properties of low-frequency components of such changes and heart rate changes calculated by analysis, a distribution of cerebral blood vessel hardness and its with-time change to thereby estimate and display diseased and dangerous portions based on the evaluation. Briefly, the above-noted object is attainable by a biological measurement system having a cerebral blood volume measurement unit which measures a regional cerebral blood volume of a body under test, an analyzer unit that analyzes a signal measured by the cerebral blood volume measurement unit, an extraction unit for extracting, based on an output of the analysis unit, information concerning a regional cerebral blood vessel state of the test body, and a display unit which displays a measurement result of the cerebral blood volume measurement unit, an analysis result of the analyzer unit or an extraction result of the extraction unit.