Abstract: An opposed type sliding door device includes a center rail mounted on a center of a door in a longitudinal direction of the door. A center roller is mounted on a vehicle body so that the center rail moves while supporting the center rail. A lower rail is mounted on a lower portion of the vehicle body in a straight line in the longitudinal direction of the vehicle body. A lower roller is mounted on the door and moves along the lower rail to pivot the door toward the outside. The lower roller further includes a pinion gear which engages in a rack gear mounted on a lower portion of the lower rail, a planetary gear reducer coupled to an upper portion of the pinion gear, and a swing bracket moving the door toward the outside with rotation of the pinion gear.