Abstract: An exemplary heat pipe includes a first pipe and a second pipe. The first pipe includes a condenser section and an evaporator section extending from the condenser section along a longitudinal direction thereof. The second pipe encloses the condenser section of the first pipe. The evaporator section is located at an outside of the second pipe. The second pipe includes a casing enclosing the condenser section, second wick structures and working fluid contained in the second wick structures. Opposite ends of each second wick structure are respectively adhered to an inner wall of the casing and an outer periphery of the condenser section.