A biological information measuring apparatus and method are provided. A pulsation information detecting unit detects heartbeat information relating to a heartbeat of a subject. A pulse wave detecting unit detects a pulse wave while a portion of the subject is pressurized and depressurized by a cuff. An amplitude calculating unit detects a cardiac cycle of a heart from the heartbeat information and a maximal value of the pulse wave in each cardiac cycle, and calculates, based on the maximal value detected from the pulse wave, at least one of an amplitude value derived from the heartbeat of the subject, an amplitude value assisted by an IABP, and an amplitude value derived from a blood flow volume of the subject. A blood pressure calculating unit calculates a blood pressure value from a relationship between the amplitude values calculated by the amplitude calculating unit and a pressurizing force of the cuff.