A sliding device, a baby seat using the sliding device, a back pack, a bag, and a belt back pack are provided, in which a carrier main body for accommodating a baby, a back pack main body for receiving goods, a carrier main body, and a carrier main body are provided in a slidably rotatable manner, and the baby can be taken down even without untying a shoulder string and the goods can be easily taken out. The sliding device includes a zipper connection member, a zipper portion in which zippers are successively engaged with each other in a length direction of the zipper connection member, and a slider engaged with the zipper portion to slidably move along the zipper portion.
