Abstract: An apparatus for measuring coal slurry at coal liquefaction condition were made. A calculation method, power number method, which suits for this apparatus were developed. The measuring range is: Re＜300, during this range, the method works well. Glycerin was taken as a standard reagent to check the reliability of the apparatus and the power number method. The results of viscosity data of a Chinese brown coal slurry were presented using the apparatus and the power number method. The viscositytemperature curve was obtained. It was found that the curve is suitable for Vogel equation at 300℃.