Background:
According to the World Health Organization (WHO) report, e-cigarette use is doubling from 2008 to 2012 among adolescents. In Taiwan, e-cigarettes contain nicotine are controlled under Pharmaceutical Affairs Act since 2009, but it will violate Tobacco Hazards Prevention Act if e-cigarettes are in the form of tobacco products. This study aims to demonstrate the prevalence of e-cigarette use and reasons for trying e-cigarettes among adolescents.

Methods:
Data were drawn from the Taiwan Global youth tobacco survey (Taiwan GYTS) conducted under a school-based and cross-sectional study from 2014 to 2016. The annual sample size is approximately 45,000 persons.

Results:
Although tobacco use by adolescents has declined substantially over the past few years, the prevalence of e-cigarette use by junior and senior high school students has risen from 2.0% and 2.1% in 2014 to 3.7% and 4.8% in 2016 respectively, both nearly doubling within this three years. 44.1% of junior high school students and 29.4% of senior high school students who have never used any tobacco product have tried e-cigarettes. “Friends are using them” and “The flavor or smell is better” are the two major reasons for trying e-cigarettes among adolescents. Our findings also show that e-cigarette use by adolescents is influenced by the views on conventional tobacco use from parents and friends.

Conclusions:
Facing the rapid development of e-cigarettes, Taiwan's governments have cooperated with each other to comprehensively block hazards from e-cigarettes by border seizure and inspection, source tracking, channel inspection, monitoring and management, education broadcasting and cessation guidance, etc. Taiwan's Tobacco Hazards Prevention Act is now in the process of amending to regulate e-cigarettes under two laws - Pharmaceutical Affairs Act and Tobacco Hazards Prevention Act - with the prohibitions on import, manufacture, and sale, persons under the age of eighteen shall not use e-cigarettes is also prohibited.