To provide a bicycle parking system which can prevent a communication cable connecting a lock mechanism of a bicycle and a management device from being damaged or from disturbing passage, and can be installed within a small space.

Each of bicycle placement stands comprises: a sensor for detecting presence/no presence of a bicycle; a lamp for indicating presence/no presence of the bicycle on the basis of a detection result by the sensor; and a lock mechanism for performing locking so as not to take out the bicycle under the presence of the bicycle. A management device is connected to the lock mechanism provided in each bicycle placement stand via a communication cable capable of transmitting/receiving signals and includes a charge deposit port for a user to pay for parking charges and a management control section for transmitting an unlock signal to the lock mechanism when the parking charges are paid from the charge deposit port. The communication cable is accommodated within bellows, the bellows are disposed on a plate which is held at an upper side of a floor surface, and a number of openings are formed substantially on the entire surface of the plate.