The findings indicated that the majority of sample groups are female 48 people or 53.33 percentage and the subordinate of sample group are male 42 people or 46.67 percentage. The majority of sample groups are between the ages of 18-20. The most popular smart phone is iPhone 28 people 0r 31.11 percentage. In a good ways, the teenagers use for convenience such as send-receive information quickly X=3.95, convenient communication X=3.8, and save money and time X=3.91. On the other hand, the smart phone has an effect on body such as losing one’s sight X=3.92, risk of accident X=3.82, and risk of crime X=3.90.