A dual seal assembly for a bearing, the assembly comprising a first seal frame (12) coupled to a tip end of an opening in a space formed between an inner ring and an outer ring of the bearing and press-fitted to the outer ring; a second seal frame (14) press-fitted to the inner ring and a main seal member (16); a third seal frame (18) interposed between the first seal frame and the second frame, and press-fitted to one of the first and second seal frames; and an auxiliary seal member (20) inserted into the third seal frame to seal a gap formed between the first and second seal frames, such that the capacity of the bearing can be increased, the bearing can be compactly designed, an operational torque can be reduced, and the sealing performance can be improved making it easy for a user to easily handle the seal assembly before the seal assembly is mounted onto the bearing and to an apparatus.