Abstract: Aim To study the hydrodynamic characteristics of falling liquid film in vertical and inclined gas liquid slug flow. Methods The liquid film velocity and its thickness along the Taylor bubble were measured by using of the high speed motion analyzer. Results The noninvasive data on the hydrodynamic characteristics of falling liquid film have been obtained. Conclusion The hydrodynamic characteristics of liquid film is related to the tube inclination angle, gas and liquid superficial velocities and Taylor bubble length, where the latter is the most important. When the mixture velocity is high enough, the flow tends to axisymmetrical so as to the influence of tube inclination angle can be neglected.