A test socket assembly which can stably transmit a signal at high communication speed comprises: a test socket having a plurality of conductive parts for electrically connecting a device terminal of the device to be tested and a board terminal of the tester board; a guide housing including a housing body having a housing opening into which the device to be tested can be inserted, and a socket supporting section disposed beneath the housing opening so as to protrude from one surface of the housing body; and a socket frame including a frame body, which is coupled to the test socket so as to be secured to the socket supporting section so that the test socket is supported beneath the housing opening, and a frame wing which is bent from the frame body toward the housing body so as to be secured to the housing body.