Measuring oxygen saturation of blood (SpO2) clinically plays a vital role in patient's health monitoring. In fact, monitoring oxygen level is necessary for people having respiratory problems (pulmonary hypertension) and in other critical conditions. The primary motivation of this work is to develop a low cost computer-based oxygen saturation monitoring system using an embedded system along with lab windows CVI platform. The process of calculating the level of oxygen saturation in the blood using non-invasive method is also called as pulse oximetry, which consists of LED and photo detectors, using MSP430FG4618 microcontroller. The MSP430 employed in designing the microcontroller firmware program for digitization and transmission of the data from sensor to the computer. NI-based Lab windows/CVI Platform was developed as a part of this project to receive, plot, save data and determine the accuracy of SpO2 value. In this proposed system, we have achieved the maximum accuracy of 99.49% which is better than the previously developed methods. The proposed system is also designed with the low cost and low power consuming modules. © 2019 National Taiwan University.