Abstract: The effects of pretreatment methods, dissolving temperature, dissolving time, and liquid-solid ratio on the dissolution rate and the precipitation rate of mulberry powder in [AMIM][Cl] were studied. The key factors and the mechanism of impedinge wood completely dissolution were discussed. The test showed that pretreatment methods and dissolving temperature were the most important factors. When wood powder pretreated with 5% NaOH dissolved at 80 ℃, and the dissolution rate and the precipitation rate was 60.20% and 46.57%, respectively. However, severe pretreatment such as ball milling or high concentrations of alkali or high temperature would exacerbate degradation. In the case of high dissolving rate but low precipitation rate, wood powder was more degradation than dissolution. On mild conditions, wood powder was difficult to be dissolved. Factors that hinder the wood powder dissolved was not solubility or riscosity,might be the formation of colloid.