A positioning system by visible light includes at least one luminaire, at least one positioning transceiver and a server. The luminaire is disposed at a specific position and has a first identification code, and emits the first identification code in a selected signal form. Each positioning transceiver has a second identification code, and further includes a receiving device and a wireless transceiver. The receiving device movably receives the first identification and demodulates the first identification code. The wireless transceiver transmits the first and the second identification codes to a receiving terminal. The server is coupled to the at least one positioning transceiver via the receiving terminal, and obtains the first and the second identification codes so as to position the at least one positioning transceiver in a space defined by the at least one luminaire.