Magneto-rheological (MR) damper is one kind of dampers using magnetorheological fluid as the working medium. The design and fabrication of a novel MR damper with parallel double coil are presented. Usually, MR damper with double or multi coil in serial is designed to obtain large damping force. This will lead to increase of MR damper length, and is not fit to limited installation space of length. The structural design of MR damper is focused to obtain required damping performance under limited dimension (especially the length). The technical originality is to propose a new MR damper configuration with the additional radial gap by double coil in parallel. The proposed MR damper is featured by the additional radial gap due to double coil in parallel. The conventional MR damper with serial double coil inevitably has two nonactive parts due to its structural features, while the proposed MR damper with parallel double coil has only one non-active part. In addition, the conventional MR damper with serial double coil has four magnetic poles, while the proposed MR damper with parallel double coil has two radial poles in addition to the four magnetic poles. A mathematical model for the proposed MR damper is developed. The conventional MR damper with serial double coil is also considered to compare damping performance with that of the proposed MR damper. The electromagnetic analysis for proposed and conventional MR damper is conducted to validate the principle of the proposed MR damper and obtain the magnetic properties of its magnetic circuit. After numerical comparison of the damping performances for the two MR damper designs, the MR damper with parallel double coil is chosen because of its better performance. The proposed MR damper is fabricated and investigated by means of experiment. According to the measured data, the proposed MR damper can provide much larger controllable damping force and almost twice the equivalent damping of the conventional MR damper.