Present disclosure relates to a heating tube, a replaceable vaporizer assembly and an electronic cigarette having the replaceable vaporizer assembly. In certain embodiments, the electronic cigarette may include an electronic cigarette body, and a replaceable vaporizer assembly. The electronic cigarette body may include a mouthpiece installed in a mouthpiece base, a connector base, a mounting base defining multiple air intake openings, an E-liquid storage tank, and a connector. The mounting base and the connector base are threadedly connected through an internal thread of mounting base and an external thread of connector base to form an air chamber inside the mounting base and connector base. When in operation, outside air enters the air chamber through the multiple air intake openings and is vaporized by the replaceable vaporizer assembly, goes up through multiple air gaps between the mounting base and the connector base, and exits the electronic cigarette body through the mouthpiece.