Abstract: The oritation technology of fruits is extensively applied in mechanical sizing and detecting of fruits. This paper theoretically analyzed dynamic mechanism of monosymmetrical fruits in transportation based on rigid body dynamics. The kinetic equation of monosymmetrical fruits in transportation was established and analyzed using the stability of Lyapunov V-function. The result showed that fruit was stable at the origin. Through dynamic simulation for oritation process using ADAMS, it was found that the rotation of ellipsoid around the maximum moment of inertia axis was stable. In addition, the oritation experiment for apricots in Xinjiang was conducted by special test device. It was obtained that the orientation success rate was higher when the ratio of the moment inertia of major diameter and riding diameter of apricots was larger, with the oritation success rate up to 88%.