The present invention provides an abnormality diagnosis system capable of identifying an abnormality occurrence site in a rotary electric machine by use of output of sensors mounted to a bearing of the rotary electric machine. The abnormality diagnosis system includes: a rotary electric machine that has a main shaft secured to a center of a rotor and supported by a bearing; a vibration sensor that measures a vibration value of the bearing; a speed sensor that measures a rotational speed value of the main shaft; and an abnormality diagnosis apparatus that diagnoses abnormality in the rotary electric machine based on the vibration value and the rotational speed value. The abnormality diagnosis apparatus includes: a database that records the vibration value, the rotational speed value, and measurement times of the vibration value and the rotational speed value, as a data group of one unit, the vibration value and the rotational speed value measured within a predetermined time period; and an abnormality determination section that makes determination of abnormality, if a first threshold is exceeded by a difference in maximum vibration value in one speed range of interest between a past data group and a newer data group of a plurality of data groups recorded in the database, and makes no determination of abnormality, even if the first threshold is exceeded by a difference in maximum vibration value outside the speed range of interest.