An　analytical　model　has　been　developed　for　analyzing　the　braking　torque　in　electromagnetic　retarder　by　flux　tube　and　armature　reaction　method.　The　magnetic　field　distribution　in　air　gap,　the　eddy　current　induced　in　the　rotor　and　the　braking　torque　are　calculated　by　the　developed　model.　Two-dimensional　and　three-dimensional　finite　element　models　for　retarder　have　also　been　developed.　Results　from　the　analytical　model　are　compared　with　those　from　finite　element　models.　The　validity　of　these　three　models　is　checked　by　the　comparison　of　the　theoretical　predictions　and　the　measurements　from　an　experimental　prototype.　The　influencing　factors　of　braking　torque　have　been　studied.　©　2014,　Higher　Education　Press　and　Springer-Verlag　Berlin　Heidelberg.