The track mechanism has high mobility on irregular terrain, and is typically used as a locomotion mechanism for all-terrain robots. However, the track mechanism sometimes slips while traversing slopes comprising loose soil. Therefore, we developed a new locomotion mechanism, referred to as surface-contact-type locomotion, which has high mobility on weak soil. It uses a simple legged mechanism that has a wide contact area with the ground so as not to corrupt the contact surface. However, it has the disadvantage of low mobility on irregular terrain. To solve the problem of the above trade-off, we developed the leg-track hybrid locomotion mechanism by fusing the two locomotion mechanisms. In this paper, we detail the developed locomotion mechanism and report some initial experiments.