Abstract: In order to solve the problems of boiler slagging and fouling caused by Xinjiang Zhundong high sodium coal during combustion, the CO2-water treatment method was ured to r emove sodium before burning, when in the mixture of coal and liquid ratioof1 : 20, maintaining a certain water temperature and stirring speed of 100 r/min with the conditions of ventilation W . ith carbon dioxide gas, different particle size of coal, the ventilation time of carbon dioxide and temperature on the influence of sodium effect were investigated. The results showed during CO2 -water pretreatment under normal temperature and normal pressure when the time of 24 hours of CO2 ventilation, while the decrease of particle size could facilitate increase the sodium remov al efficiency, sodium removal efficiency reached 86 .8% when particle size of coal was 0.1 ~ 0.2 mm. Under the normal temperature and atmospheric, It could be removed large amounts of wat er soluble sodium and part of the organic sodium after six hours with carbon dioxide, sodium removal efficiency reached 83. 1%. When the temperature rose to 40°C, it increased the removal ef fect of water soluble in sodium, sodium ammonium acetate solution, dilute hydrochloric acid soluble sodium in coal, sodium removal efficiency could reach 88 3%, which had reached the requi rements of coal burning boiler.