A liquid film flowing down along a heated solid plate may be remarkably influenced by Marangoni effect. This effect is usually generated by the existence of surface tension gradient that is induced by variations of surface temperature in the transverse direction of the film(due to the flow rate difference between film center and rim)

causing notable contraction of the film. The shrinkage effect interacts with the liquid wetting ability and the expansion effect induced by the mass flow

resulting in distinct bulgy structure in the cross-section of the film rim. A mathematical model describing the characteristics of the heated film was derived by taking into account the effect of surface tension gradient on the film flow

as well as the force balance and mass conservation in the bulgy structure. The model indicated that low surface temperature

small liquid-solid contact angle and large mass flux could benefit preferential extension of the liquid film on a solid plate. The comparison of the model with the experimental data

showed that the model could satisfactorily describe the flow characteristics of a falling films on a heated plate. It is expected that the model can be used as a theoretical basis for optimal design and operation of falling film process and equipments.