A new front end readout circuit for non-invasive, cuff-less, convenient blood pressure sensor is proposed in this study. The blood pressure sensor features continuous detection, low power and low cost. The sensor is able to detect pulse signals of the artery vibration under the skin of a human wrist. The front end circuit consists of a sensing circuit, an amplification, a peak-sensing circuit and a counter. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 μ m 1P6M 1.8V mixed - signal CMOS process. The proposed chips with the die area of 1.35×1.13mm2 and 1.37×1.37mm2 are fabricated by National Applied Study Laboratories National Chip Implementation Center (NARL NCIC). The front-end readout IC is simulated and experimented. The pulsation amplitude in terms of output voltage of readout circuit is successful to a satisfactory accuracy of the BP sensor to be within 5 mmHg, lower than 8 mmHg, a standard by Association for the Advancement of Medical Instrumentation (AAMI).