Abstract: Formation of fractures is an important geological phenomenon which produced break and displacement of rocks by crust stress．From the mathematical viewpoint the observed spatial distribution of fractures is a series of irregular line-shaped and plane-shaped geometric body set. Regarding the irregular-shaped geometric body set as a fractal body，the fractal dimension of spatial distribution characteristics d fractal body can be quantitatively calculated by using fractal geometric method. The NE and NNE fracture systems of antimony mineralized zones in central Hunan control the migration of ore-forming fluid and location of antimony deposits in the region. In present paper，the principles and methods of information dimension are applied to the study of fractal characteristics of the two- dimensional distribution of fracture system in the antimony mincrafized zones, centra1 Hunan. The research of the information dimension (D1) of fracture system considers the contribution of each fracture to information reflects the characteristics of spatial distribution of fracture from a new point of view，and avoids the shortcomings of the fractal dimension of capacity(DO). The results of calculation show that the information dimension of fractures in three antimony mineralized zones are 1.706, 1.810 and 1.593 for Simingshan zone. Xikuangshan-Longshan zone and Dashenshan zone respectively. The difference in information dimensions of fracture system in antimony mineralized zones quantitatively describes the fracture intensity and fracture distribution. It also shows that these three antimony mineralized zones of centra1 Hunan belong to three self similar systems with different information dimensions. Integrating with the characteristics of antimony deposit distribution of al1 zones, it can be noted that the numerica1 value of information dimensions for fractures can trace the migration of ore-forming fluid and indicate the location of antimony deposits. The more the antimony deposits and the larger the ore reserves，the higher the Information dimension values.