Abstract: A guiding device includes a straight track, an arc track, and an interconnecting track joining the former two, where the interconnecting track has two opposite rolling contact surfaces, one with the profile being identical to that of the arc track and the other with a variable-curvatured profile. Only two rolling members are provided to roll on the side of the arc profile and only one rolling member is provided to roll on the side of the variable-curvatured profile, achieving a result that the rolling members driving a movement of a moving body remain contact with corresponding tracks in their rolling motion so as to improve stability and smooth transition of the device in motion.