First, addiction to social media makes the youth have bad grades in studies. Because of social media, many students who were excellent students have become bad students. Every day, these students come to class, but they do not focus on studying. While their professors are teaching, they are using cellphones to surf Facebook, Instagram or chat with friends on Messenger. They always check their cellphones every five minutes to see what is going on on social media. If the young use social media in classes, how can they listen to the professors and understand what professors are saying? Moreover, not only at school but also at home these young students who are addicted to social media do not do exercise or read the new lesson before going to school, because they are busy with social media. For example, Khanh, a young girl from Vietnam, is addicted to social media. In the past, she was a hard-working student. She always did all homework and prepared for new lessons, so she got A grades. However, everything has changed since she started using social media too much. In classes, instead of listening to the professor, she always posts selfies on Facebook and Instagram. At home, with the attraction of social media, she continues using her cellphone and does not study or do assignments. As a result, in the mid-term exam and final exam, she only got C and D grades. Addiction to social media causes a bad habit in studies. It can change a young person from an excellent student to a bad one.