To provide a rental cycle management system useful for a small scale rental cycle system capable of managing rental cycles with a small number of persons without using a computer.

The rental cycle management system is provided with an entrance gate 8 to be automatically opened/closed when an entering person or a rental cycle returning person inserts a prescribed card such as a member's card and a commuter's ticket and an exit gate 12 to be opened for an exiting person or a cycle borrower under the monitor of a custodian or by custodian's operation. In this case, a prescribed management number is annexed to each rental cycle and a signboard on which the management number is written is prepared in each rental cycle. A cycle borrower presents the signboard to the custodian and borrows its corresponding cycle and the custodian stores the signboard in a prescribed place. When the borrower returns the cycle, the custodian can check the cycle and its borrowing period by checking the stored signboard.