A system for the coexistence between a plurality of wireless communication modules sharing a single antenna is provided, including an antenna, first and second transceiving paths, and first and second wireless communications modules. The first transceiving path is coupled to the antenna. The second transceiving path is coupled to the first transceiving path. The first wireless communications module is coupled to the first transceiving path and transmits or receives a plurality of first wireless signals. The second wireless communications module is coupled to the second transceiving path and transmits or receives a plurality of second wireless signals, wherein signal strengths of the second wireless signals passing through the second transceiving path are attenuated by a certain level, and the attenuated second wireless signals are added to the first wireless signals when passing through the first transceiving path.