Recently, interest in concrete quality has been increasing. It is important to manage these factors due to unit-water content and aggregate quality that affect concrete quality. In this study, the unit-water content of concrete was measured through an economical, easy-to-measure, and portable Frequency Domain Reflecmetry sensor among micro-methods that compensated for the shortcomings of existing concrete unit-water content measurement methods. As a result of predicting the unit-water content, the accuracy within the ± 10 kg/㎥ error range was confirmed to be more than 72% of all factors. In order to ensure high accuracy, it is considered necessary to conduct an experiment to evaluate the unit-water content by conducting additional experiments according to other variables and factors.