Abstract: Using physical property analyzer, complete random compression mechanical property tests were conducted on mung bean grains under four moisture contents（11.2%, 13.2%, 15.2%, 17.2%）and three loading speeds（1.2 mm/s, 2.4 mm/s, 3.6 mm/s）through uniaxial compression, obtaining compression load displacement curve, yield load, deformation amount, breaking energy and apparent elastic modulus of the grains．Results showed that load displacement curve of grains under natural compression had a clear biological yield point．At the same loading speed, moisture content had a significant impact on yield load and apparent elastic modulus of grains．When moisture content was 11.2%, yield load, breaking energy and apparent elastic modulus of grain were maximum, and deformation amount was minimum．However, as moisture content increased, yield load, breaking energy and apparent elastic modulus of grain basically showed a trend of decreasing first and then increasing, and deformation amount showed a trend of increasing first and then decreasing．When moisture content was 13.2%, yield load increased with increase of loading speed．But at the same moisture content, deformation of grain basically decreased with increase of loading speed, and variation of grain breaking energy and apparent elastic modulus with loading speed was similar to yield load of grain．When moisture content changed within experiment range, effect of loading speed on compressive mechanical properties of grains was not significant．