A wettability measurement was conducted as one of the physicochemical properties of surface composite fine particles. The particles were prepared by high-speed gas impact blending. To evaluate the wettability, the capillary rising velocity of water in a packed bed of composite fine particles was measured continuously by means of an electronic balance. This measurement is based on Washburn＇s theory on the penetration rate. The experimental results showed that the wettability of the packed bed increases with the coating ratio of the hydrophilic fine particles over the composite surface. It also increases with increasing voidage, which reduces the effective penetration area, and decreases with sinking extent.