In the paper the influence of moisture content w of spring wheat grain of Alfa variety on the intensity Im of ultraweak luminescence UL emitted at the initial stage of its swelling, during ten minutes after soaking the grain in distilled water, is investigated. The investigations were carried out on undamaged grain and grain subjected to static mechanical stress of 6 MPa. The moisture content of grain was in the range of 8.3 % to 22.7 %. The measurements were performed using a high sensitivity quantum-metric apparatus working in the single photon counting arrangement. Higher values of intensity Im were obtained for the lowest moisture content of grain and for the grain mechanically damaged. In both cases the dependences of Im on may be described as an exponential function.