A performance testing apparatus for a heat pipe includes an immovable portion having a heating member located therein for heating an evaporating section of a heat pipe requiring testing. A movable portion is capable of moving relative to the immovable portion and has a heating member therein for heating the evaporating section of the heat pipe. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. A positioning structure extends from the immovable portion to ensure the receiving structure being capable of precisely receiving the heat pipe. Temperature sensors are attached to the immovable portion and the movable portion for detecting temperature of the heat pipe.