Abstract: The difference in height between the collar stand and the collar is one of the main factors affecting the design of gradient data of lapel collar.Based on the design principle of the lapel collar,a mathematics model of the relationship between lapel ease,collar width and gradient data is established and its feasibility is verified by experiments.Provided that the height of collar stand remains constant,the lapel ease and gradient data of lapel collar increase with the increase of the collar width,but in the case of increment,the former almost keeps linear increase tendency,whereas the latter exhibits a progressive decrease.Moreover,in order to get a good collar,the collar stand must be made so that it can be detached,thus ensuring a fit collar stand and a natural turning of a collar.