The crown inclination, representing an angle formed by the clinical crown axis and a line which bears 90 degrees to the occlusal plane, reflects the labiolingual or buccolingual inclination of the long axis of the crown. The crown inclination is related to the races. And it is compensated by different vertical or sagittal jaw relationships. It plays an important role in fine occlusal relationship and achieving functional, artistic and stable treatment goal. The torque design of the straight wire bracket is based on the normal crown inclination. There is much discrepancy in the torque design of the different straight wire bracket because of the different race and philosophy. This review gave a brief introduction of the influential factors, the clinical meaning of the crown inclination and the torque design of the different bracket system.