The hydraulic fracturing problems in fields of water conservancy and hydropower and mining are produced by natural hydraulic power. Its boundary conditions are different with them in artificial hydraulic fracturing applied to fields of petroleum and natural gas. The characteristics of hydraulic fracturing under natural power are generalized. The study level of hydraulic fracturing is divided into two based on study measure. The one is based on macroscopical
synthetical and statistical characteristics medium. The other is focused on a single fracture and a group of fracture with regular location. The characteristics of fracture flow are analyzed. In order to simplify the research
the hydraulic fracturing process of a single fracture can be divided two stage or two kinds. The different fracture flow models are proposed.