A performance testing apparatus for a heat pipe includes an immovable portion and a movable portion each having a heating member for heating an evaporating section of a heat pipe requiring test. The movable portion is movable relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion to ensure the receiving structure being capable of receiving the heat pipe precisely. Temperature sensors are attached in the immovable portion and the movable portion for detecting temperature of the heat pipe.