Smart phone is the essential digital gadgets that teenagers nowadays have. However, despite the convenience it brings to use, sometimes it might affect our daily life in a negative sense. One of the typical examples is the overuse of smartphone. Smart phone can easily get our attention and distracts us. People, especially students, therefore are easily overusing the smartphone. The distractions lower students productivity and takes their time. It also lowers the quality of the work done. In this essay one cause and three effects of overusing smartphone will be discussed.