An object of the present invention is to provide a method and apparatus capable of evaluating the fluidity of blood according to the diversity of subjects and clearly detecting aspects of subjects in various blood vessel states and blood flow states. In the present invention, the pressing member is pressed against the test site of the subject with the pressure of the primary pressure, the blood in the test site is caused to flow out to the periphery of the test site, and then the pressure for pressing the pressing member to the secondary pressure Then, the pressure for pressing the pressing member is released, and then a pressing cycle for increasing the pressure for pressing the pressing member to the primary pressure is performed a plurality of times, and the time of the blood volume in the test site therebetween Measuring the change using light scattering, wherein the value of the secondary pressure has at least two different values over a plurality of pressing cycles.本発明の課題は、被験者の多様性に応じて血液の流動性を評価し、多様な血管状態、血流状態の被験者の態様を明瞭に検出し得る方法及び装置を提供すること、である。本発明は、被験者の被験部位へ押し当て部材を一次圧の圧力で押し当て、被験部位内の血液を被験部位の周辺に流出せしめ、次いで、押し当て部材を押し当てる圧力を二次圧にまで低減せしめ、次いで、押し当て部材を押し当てる圧力を開放し、次いで、押し当て部材を押し当てる圧力を一次圧にまで高める押し当てサイクルを複数回行って、その間の被験部位内の血液量の時間変化を光散乱を用いて計測する工程を有し、二次圧の値は複数回の押し当てサイクルにわたって少なくとも2個の相異なる値をもつ、血液流動性の評価方法を提供する。
