A semiconductive rubber composition is provided having superior electrical properties, such as superior uniformity, small voltage dependence, small environmental dependence, and stability with time. In addition, the semiconductive rubber composition can be used for forming a charging member which suppresses contamination of a member to be charged, such as a photosensitive member. In the semiconductive rubber composition, a dispersed domain structure is formed having a polymeric continuous phase composed of an ion conductive rubber material primarily containing a raw rubber A having an intrinsic volume resistivity of 1×1012 &OHgr;·cm or less and a polymeric dispersed phase composed of an electron conductive rubber material and conductive particles mixed therewith.