Method of measuring blood circulation velocity by controlling breath

This present invention is related to a method of measuring blood circulation velocity by controlling a person's breath. The steps of the method includes keeping the person in a first breath status with a cardiovascular signal detector, setting an initial time point and starting to record cardiovascular signal values per a predict time interval, requesting the person to change into a second breath status at a first time point, requesting the person to change into a third breath status at a second time point, setting a reference time point according to a cardiovascular signal value which has a variation, and obtaining the person's blood circulation velocity is proportioned to the inverse of the difference of the reference time point and the first time point.