Cyber bullying refers to those malignant behaviors of an individual or a group that aim to hurt others in an intentional and repeated way through information dissemination technology. Survey data show that cyber bullying is a pervasive phenomenon among minors in the world, and there exists gender variation between men and women: more girls are found in cyber bullying than boys. This study describes the situation with domestic and international cyber bullying, and analyses the characteristics of and causes for cyber bullying. It also identifies some measures to prevent cyber bullying. <<