Abstract: As a by-Product of coal cleaning plant,coal slime is characterized by its high moisture and viscosity and viscosity and low calorific value,a nature making it impossible to be utilized as an energy on an extensive basis. Viewed from the existing technological conditions,thermal drying is the most effective approach and basic means for the upgrading of coal slime. The paper presents an analysis of the thermal drying technologies currently applied in China’s coal preparation plants and a forecast of their developing trend.