Surfing the internet can be an interest for people. But people need to use it properly. If not, it will become internet addiction. Internet addiction harmfulness is bigger than “TV addiction”. In deed internet addiction can be called “a mental illness”.Playing online games reasonably can make people happy on free time. People also can increase the relationships between friends by rational use of network. Indisputably, network is a good way to find the information. Then, buying something online is very convenient. But doing anything need moderately. Otherwise it will be bad for people. There are some way to treat the online addicition. people can go outside to do some sport. Then people do not have energy to play computer. Also, people spend time to chat with friends at real life. It is good way to improve the friends relationship.