Abstract: The present disclosure relates to electronic cigarettes having vaporizer assembly with “U” shaped air path and methods of using the same. The electronic cigarette includes: mouthpiece assembly, electronic cigarette body, E-liquid storage tank having a negative air pressure cavity and a number of airflow channels forming “U” shaped air path, and the vaporizer assembly. The vaporizer assembly includes: one or more cylindrical E-liquid storage media, and one or more heating elements. The elements are electrically connected to an electrical power supply through negative air pressure activated switch. When a user sucks air from mouthpiece assembly, a negative air pressure is created in the negative air pressure cavity, the negative air pressure activated switch turns on the electrical power supply to the heating elements, and the heating elements vaporize the E-liquid stored in cylindrical E-liquid storage media to generate electronic cigarette vapor for the user through the “U” shaped air path.