A performance testing apparatus for a heat pipe includes an immovable portion having a cooling structure defined therein for cooling a heat pipe requiring to be tested. A movable portion is capable of moving relative to the immovable portion and has a cooling structure therein for cooling the heat pipe. A receiving structure is located between the immovable portion and the movable portion for receiving the heat pipe therein. At least one temperature sensor is attached to at least one of the immovable portion and the movable portion. The least one temperature sensor has a detecting section exposed in the receiving structure for thermally contacting the heat pipe in the receiving structure to detect a temperature of the heat pipe.