The objective of this study was to study factors influencing risk consuming behaviors of Thai youth aged 15-24 years in Kanchanaburi Demographic Surveillance System (DSS) area in western region of Thailand. Risk consuming behavior included smoking and drinking alcohol such as beer, liquor and traditional liquor. It was found that 16.7% teenage in Kanchanaburi DSS smoke cigarette with 32.4 % of them males and 2.9% females. Late tanagers aged 22-24 years (27%) were smoking more than early teenager aged 15-17 years and middle teenager aged 18-21 years. Teenagers with no or less than primary educational level (35.7%) were the greatest smoker group. Concerning beer drinking, 21.6% of teenagers in Kanchanaburi DSS drank beer with 41.1% of them males and 4.5% of females. Late teenagers group (31.9%) were drinking beer more than other teenager groups. Teenager with undergraduated or higher level (26.5%) were the greatest beer drinking group. Regarding liquor drinking, 17.6% of teenagers in Kanchanaburi DSS drank liquor with 35.1% of them males and 2.0% of females. Late teenagers group (27.8%) drunk liquor more than the other teenagers’ group. Teenagers with undergraduated or higher level (23.1%) were the greatest liquor drinking group. It was discovered that, 3.2% of teenagers in Kanchanaburi DSS drink traditional liquor with 6.4% of them males and 0.4% of females. Late teenagers (5.9%) were the greatest traditional liquor drinking groups. Teenagers with primary level were drinking traditional liquor more than the other educational groups. The most statistically significant factors in risk consuming behaviour of youth in Kanchanaburi were sex, age, education and residential area factors ( p-value 0.05). The data from in-dept interview supported that there are many reasons involved in the decision of youth smoking and drinking behaviour; for example, friend’s persuasion, curiosity, following friends, social association, feeling of maturity, stresses, broker heart, having problems, environment and adult imitation.