An electronic cigarette, including a mouthpiece assembly, an atomizing assembly, and a base assembly. The mouthpiece assembly includes a mouthpiece, a first seal ring adapted to seal the mouthpiece, a decorative ring, a first fixed seat adapted to fix the mouthpiece, a second seal ring adapted to seal the first fixed seat, a decorative cover, a fixed cover, a fixed ring adapted to fix the fixed cover, and a slide block. The atomizing assembly includes a silicone seal, a pin, a spring, a second fixed seat adapted to fix the slide block, a vapor regulating ring, a second seal ring adapted to seal the vapor regulating ring, a glass tube, a third seal ring, a fourth seal ring, and an atomizing unit. The base assembly includes a fifth seal ring, a base, an insulation ring, and a joint.