A rack system includes a rack, a supporting assembly, an object to be carried, and a blocking kit. The rack includes a front post and a rear post. The supporting assembly is mounted on the front post and the rear post. The object is carried by the supporting assembly. The blocking kit includes a connecting base and a blocking member. The connecting base is mounted on the front post, and the blocking member is arranged at the connecting base. When the object reaches a second position after displacement from a first position, the blocking member is at a locked position to block the object and thereby prevent the object from displacement from the second position in a certain direction.