This paper presents the kinematic analysis of a common rapier mechanism using three dimensional closed loop method. Also a new rapier mechanism using an elliptical gear set as a driving system in order to improve the inserting motion of the rapier is proposed. The elliptical gear set proposed in the paper can transmit the exact cyclic motion to the rapier mechanism as the driving motion. Although a driving gear on the main shaft rotates at a constant velocity, a driven gear has a variable velocity ratio on an instant contact point. By using an elliptical gear set, smoothness of the inserting motion of the rapier is obtained. The proposed mechanism improves the characteristics of the common rapier, resulting in an increases in the available width of the fabric. This paper presents the comparative data of displacements and velocities of two system.