A pulse wave data analyzing method includes successively detecting bottom and top peak values of pulse wave data along a time axis, calculating successive bottom-to-top amplitude values along the time axis, and comparing first and second peak-to-peak amplitude values occurring in succession along the time axis. If the ratio of the second peak-to-peak amplitude value to the first peak-to-peak amplitude value is smaller than a preset threshold, the bottom and top peak values related to the second peak-to-peak amplitude value are classified as temporarily erased data. The second peak-to-peak amplitude value is compared with a third peak-to-peak amplitude value occurring immediately thereafter and, if the ratio between the second and third peak-to-peak amplitude values is larger than the threshold, the temporarily erased data is restored. If the ratio between the second and third peak-to-peak amplitude values is not larger than the threshold, the temporarily erased data is completely erased.
