The only one ground fissures geological disaster along the middle route of the South-to-North Water Transfer Project (SNWTP) is the Baizhuang Ground fissure. In order to analyze the causes for the fissure development, the distribution and morphological characteristics of the ground fissure were investigated. And the influence of subsidence caused by the coal mining, the fracture structure of the JiuLi mountain, the effects of the stress relief, the conditions of the environmental geological and the effects of the ground water were studied. The results showed that the ground fissures were not caused by the subsidence of the mined out area, and the development of the ground fissures was mainly controlled by the fracture structure of the JiuLi mountain. Other environmental and geological conditions (i.e., the stress release caused by mining activities, the ground water decline, and the surface water infiltration) also had a synergic effect on the ground fissures. The cause analysis and preliminary monitoring showed that the activity of the ground fissure still existed but its strength was weak, and the ground fissure activity tended to be stable as a whole.