Abstract: To analyze the working performance of the transplanting mechanism with planetary elliptic gears for pot seedling transplanter which was proposed in this paper, the kinematic model of this mechanism was established, and the equations of (angular) displacement, (angular) velocity and (angular) acceleration for transplanting tip were deduced. On this basis, the kinematic simulation and optimization software of the mechanism was compiled by Visual Basic 6.0. Besides, the influence of several main parameters on the working performance of the mechanism was analyzed by this software. These main parameters included the semi-major axis of elliptic gear, the ratio between minor axis and major axis, the initial installation angle of the planet carrier and row spacing. And working performances included hole size, trajectory attitude of transplanting tip and its verticality, and operational stability of the mechanism. According to the analysis results, a group of preferable mechanical parameters were obtained. The corresponding working performance, such as the trajectory and posture of transplanting tip, can meet the agricultural demands of vegetable seedling transplanting with smaller speed fluctuation and acceleration fluctuation in comparison with reciprocating transplanting mechanism.