In a system for testing antenna performance, antenna performance is tested by reflecting the loss of a cable used in the antenna performance test. The system for testing antenna performance includes a tester having a test port, the test port being connected, via a cable, to an antenna that communicates with a terminal to be tested, in a shield box, when a test mode is set, wherein the tester outputs a test signal to the test port, receives a response signal corresponding to the test signal via the test port, and obtains a value, as a communication performance measurement value, by adding a calibration value to a reception signal strength of the response signal.