Abstract: The sliding bubble plays an important role to enhance heat transfer. The secret understanding of the sliding bubble motive characteristic is required in order to constitute the reasonable mechanism models. The momentum equation on the sliding bubble was established according to the analysis of forces acting on the sliding bubble in horizontal flow boiling, and the velocity of the sliding bubble was obtained by numerical solving method. The prediction results were compared with the experimental results of Maity, and they agree very well. The velocity of the sliding bubble increases with increasing time, but the increase of the sliding velocity for bubble decreases gradually. The velocity of the sliding bubble is less than that of the local liquid, which shows that the drag force and add-mass force due to bubble expansion are driving force to make the bubble slide along the wall, and the shear lift force is driving force to make the sliding bubble lift off the wall.