To obtain a magnet ring for steering angle sensor which can simplify the manufacturing facility and reduce the material loss, and at the same time, can be efficiently formed in a high quality.

A ring body of a appropriately selected size is divided equally in the circumferential direction into three rubber magnet divided pieces 2a, 2b and 2c. The divided pieces are used and assembled in a ring body, thereby, a magnet ring body is formed. The magnet ring body (each of rubber magnet divided pieces 2a, 2b, 2c) is magnetized to have a predetermined magnetic field distribution. The magnet ring for steering angle sensor and its manufacturing, method in which the manufacturing facility can be simplified and material loss can be reduced, and at the same time, the magnet ring can be efficiently formed in a high quality, can be obtained.