Abstract: The dynamic mechanical properties of dry and water-saturated fast-growing poplar wood under dynamic compression was investigated by the split Hopkinson bar techanique and compared with the quasi-static compression experiment. The failure mechanism of the poplar wood discussed at high strain rates. Results show the following characters: (1) the compressive stress-strain curves of poplar wood are similar to those of other cellular solids which are characterized by three distinct region: elastic region, collapse region and densification region; (2) the fibers of the dry poplar samples after shock occur local bucking and collapse, but the fiber bundles of the water-saturated poplar samples detach along the grain direction due to the water in the cellular lumens which is incompressible and can not be extruded at high strain rates. (3) the strain rate effect of the poplar wood is evident.