A non-invasive blood pressure measuring apparatus includes a host provided with a microprocessor coupled with an air pressure sensor. A pressurized cuff is an inflatable cuff with a gas tube connected with the air pressure sensor, and fastened to a body portion where users artery blood flow can be blocked completely after air inflation. A pulse wave detector is fixed at a downstream position of the pressurized cuff according to the artery blood flow direction. The microprocessor performs a real-time process to several pulse wave amplitudes detected by the pulse wave detector during the course of slow increase from zero and the corresponding pressures of the pressurized cuff to determine a systolic pressure and the microprocessor performs a real-time process to several pulse delay periods which are the delay periods between the pulse waves and the corresponding pressure AC signals during the course of variable delay periods to relatively constant delay periods and the corresponding pressures of the pressurized cuff to determine a diastolic pressure.
