A blood rheology measuring apparatus has a measuring portion for measuring a flow velocity of the blood flowing in a blood vessel of a person in a mode of a Doppler shift signal by transmitting and receiving a wave to and from a surface of the person's skin. An information processing portion calculates an intensity at each of frequency components of the Doppler shift signal, extracts a maximum frequency in a signal at an intensity level equal to or larger than a threshold in the histogram or a maximum frequency when an integrated value from a low frequency component reaches a predetermined rate of a total thereof in the histogram, and provides a temporal change waveform of the extracted frequency. The blood rheology is analyzed based on the maximum frequency in the frequency waveform.