Abstract: A device for measuring moisture content of soil and snow water storage has a first detector of cosmic neutrons passed through the soil placed deep in the soil at a pre-set depth, a second cosmic-ray neutron detector placed above the soil at an altitude which is greater than maximum snow pack thickness or vegetation layer height and spaced from the first neutron detector at a distance which is not greater than the path length of thermal neutrons in the atomosphere, and a soil background gamma-quantum radiation detector placed on the soil surface and spaced from the first neutron detector at a distance which is not greater than the gamma-quantum path length in the soil. Outputs of the neutron detectors and gamma-quantum radiation detector, are coupled to a respective series circuit, including a unit for detecting pulses of a predetermined amplitude, a pulse counter to which is connected a timer, and a recorder.