In this article we explored a toilet training process for a 5.5 years old, mild mental-retard child. The toilet training program was set on Wednesday afternoon in a hospital and was divided in two sections. The first section was performed from April 8, 2010 to May 26, 2010 and ended for the reason of the enterovirus infection and the child's parents need to prepare themselves for the new job. Two months later, the child experienced the same toilet-using difficulty problem. Thus, the second section was performed from August 12, 2010 to September 29, 2010 in the same hospital. The child had cognitive and social skill problems. She was obviously of insufficient development and had learning, communication, toilet-using habit, and school-refusal problems. It's afraid that the child hardly can adapt her school life in the kindergarten. Therefore, we applied behavior therapy and toilet training to help her use toilet alone. It turned out that the training program of copping with the difficulty in toilet using successfully improved her school life in the kindergarten.