A heat pipe includes a pipe member, a bottom lid and a wick structure. The pipe member includes a plurality of longitudinal grooves radially arranged on an inner sidewall thereof. The bottom lid covers a bottom end of the pipe member. The wick structure includes the grooves and sintered powders attached to an inner surface of the bottom lid. Thereby, the sintered powders does not need to be attached to the inner wall of the pipe member so that an axial bar is no more need. Such that, the damage caused by removal of the axial bar are prevented and the fabricating process of the heat pipe is simplified.