An improved electric radiator filled with oil includes a plurality of radiating fins, an electric-control box and a heater. Within the electric-control box, a switch, a temperature controller, a heat protector and a wire are provided. The radiating fin is hollow and sheet-like with at least two grooves therein for leading oil. The upper and lower ends of the fins are provided with hollow connecting-sleeves, oil-inflow holes are formed inside the connecting-sleeves. Each of the radiating fins is communicated with the oil-inflow hole and is filled with oil. Either the upper and the lower ends of each radiating fin are in different vertical planes, or the upper and the lower ends of each radiating fin are in a same vertical plane, but at least a part of the middle of each radiating fin is curved to form a convex configuration towards the side. Each of the radiating fins has the same shape and dimensions.