A rubber composition contains a higher ethylene content EPDM and a lower ethylene content EPDM as a rubber component. The proportion of the higher ethylene content EPDM is 30 to 80 mass % based on the overall amount of the rubber component. The rubber composition is less susceptible to reduction in friction coefficient μ and has a proper hardness, a smaller permanent elongation and an excellent abrasion resistance after crosslinking. Therefore, the rubber composition is suitable for a sheet conveying roller and an image forming apparatus incorporating the sheet conveying roller.