Features of the strains in some southern hardwoods during the first drying stagewere studied under various temperature and equilibrium moisture content.The results shownthat surface layer represented tensile elastic strain and plastic strain , while internal layerrepresented compress strain. The maximum tensile elastic strain was the main factor whichresulted in surface-checking,and the set caused by plastic strain was the reason of inner-checking.The elastic and plastic strain were greatly influenced by the equilibrium moisturecontent and interrelated with the MC gradient.Drying time during the first drying stage bedetermined by the ratio of the MC when the surface reached the maximum tensile strain andthe initial MC.