Abstract: The present invention relates to a junction box comprising a housing, an electric connection module, a monitor module, and a cable module. A solar module transmits electricity generated by the solar module to a power conversion device; moreover, a plurality of signal wires of the cable module transmit the parameter supervised by the monitor module to an external monitoring and controlling device at the same time. Therefore, the monitor module can inform users the using information of the solar module such that users can judge the timing of repairing and replacing the external solar module and so as to achieve an ultimate using benefit of the solar module.