A pallet unit and conveying system for conveying long workpieces features that the conveying direction can be quickly changed without increasing apparatus space. Said pallet unit has two circular pallets, which are arranged at both ends of a connecting rod and can rotate around vertical axis. When said circular pallets move from conveyer A to conveyer B, it is unnecessary to stop the conveyers and they sequentially move to next conveyer under the guide of a direction changing guider.