The present invention discloses a carrier, which comprises a core and a resin coating layer formed thereon containing electroconductive powder, wherein, when the magnetic brush is formed only of the core, the dynamic electrical resistance of the core forming the magnetic brush under an electric field of 104 V/cm is 1 &OHgr;·cm or less and the electrical resistance of the resin coating layer is from 10 to 1×108 &OHgr;·cm, a developer using the carrier, and an image-forming method using the developer. Owing to the present invention, a superior solid image, which is free of brush marks and carrier beads carry over, can be obtained.