Abstract: An apparatus and a method for expressing wetting and drying on an object surface are provided. The apparatus includes an adding water mark module adding new water on an object surface from a particle or a mesh representing water in outside environment, a wetting module considering water affinity of the object surface, a 2D fluid simulation module processing a flow of water particles in excess of a wet capacity of the object, and a drying module drying a drying wet portion after a predetermined time elapses. Moreover, a characteristic change of the object surface can be expressed, which is caused by water contact in the object surface interacting with water, and also water affinity can be expressed using a wetting capacity and a drying time. Therefore, detailed expression of water is possible when water exists in a scene, and various scenes with water can be depicted more realistically, which is a very important component of special effects.