In this paper, a kind of imidazolium ionic liquid, 1-butyl-3-methyl imidazolium chloride ( [BMIM]Cl) was synthesized, and the chemical structures of the ionic liquids were characterizaed by FT-IR and NMR. The solubilities of the ionic liquid for duabanga grandiflora powder activated with different modified conditions were studied respectively. Dissolution rate of wood pretreated with about 25% NaOH solution was the best , due to the reduction of the hydrogen bond applied force. The chemical structure and crystal behavior of duabanga grandiflorar powder before and after dissolution were analyzed by FT-IR and XRD, respectively. The dissolution mechanism has also been discussed. The results showed that the ionic liquids had a good solubility for cellulose in activated duabanga grandiflorar powder. Micrographs of the original wood powder，regenerated wood powder and the residua were quite different from each others. The regenerated wood appeared some micro voids special construction.