The slip-over phenomenon is a very interesting feature in rapid writing Chinese characters, a unique psychological phenomenon in Chinese language. Most of the slip-over characters appear in set phrases. It is just like a walking man, when he is in a hurry he would sometimes run one or two steps. Since most Chinese characters contain radicals, slip-over phenomenon occurs quite frequently. In this paper the author lists four groups of slip-over characters and analyzes their psychological processes. The author holds that this study is useful, in some ways, in their use in computers.