In this study, we propose using the propagation velocity of radio waves as a means to measure the body water content of the human in a no-ncontact manner. The propagation velocity is depending on the medium, and it reduce speed in the water compared to in the air. Using this property, we considered to measure the body water content by measuring the propagation time until the radio wave to be transmitted passes through the human body. If this measurement becomes possible, it can be expected to measure body water content in non-contact. We conducted an experiment to irradiate water to microwave as a basic experiment and evaluated the propagation delay time accompanying the increase in water content, so we report the result in this paper.