Ghost-free image is significant in single-component development system. A low resistance development roller can exclude the ghost due to the charge accumulation on the surface of development roller, but it is not sufficient to achieve the ghost free image.To explain the ghost mechanism, it is effective to calculate and study the relation between development characteristics and major parameters, such as toner mass per unit area and toner charge per unit mass.We have experimentally found out the relation between the ghost and the toner particle diameter transition on the development roller, and theoretically explained the ghost mechanism. On the basis of these results we propose the ghost-free development system by using a reset member which restricts the toner particle diameter transition.