A method to measure water content in porous media, such as soils and grains, was developed as a real time nondestructive test. The method was based on piezoelectric ultrasonic transducers as a sensor system. Transmitters and receivers was developed to administrate the sensors system and ultrasonic signal. Transmitters and receivers are placed facing each other and located inside the porous media 10 cm apart. The method was evaluated in two porous media, namely a column 30 cm coarse sand and a paddy rice variety Fedearroz 50, in order to evaluate the sensors system performance in two different porous media with different water holder capacity. Tools were developed for data acquisition, capacity of 16 analog signal, 12 bits resolution. Electronic circuits, C++ OOP programming and Matlab were used. The results showed a monotonically increment of millivolts as a response of the transducer as the water content was decreasing.