Firstly, managing of time is good. According to the result of Cambodian study confirm the students who use their mobile phone in class on regular basis have low grade. While the teacher is teaching they do not have concentrate to the lesson because they are interested in their mobile they don’t listen the lesson. So, they do not understand in the lesson and cannot do their homework. In addition, using mobile phone in class. It’s made their student poor health. Looking mobile’s screen for a long time will make bad eyesight and have a headache. Therefore , student who use their mobile phone in class have chance get poorer health and lower grade than other students who never use mobile phone in class.