Some really good clear advice from Tommy. I agree with almost all of his grammar suggestions -  really excellent advice.

He did suggest that you add an opinion to the thesis sentence. I think this is a good idea, but it's not absolutely necessary. I recommend that people do it, but you can also leave your opinion to the end.

If you give your opinion in the thesis it can help the reader, and it can also help you by forcing you to make your mind up! You wrote:

In this essay I will analyse how does computer games affect to children.

Here's a possible rewrite:

In this essay I will analyse how computer games affect children and say why I believe parents need to restrict what games their children play

The second point Tommy makes is about the length of Paragraph Three. Here I agree with him again. Try to make your paragraphs and arguments the same length. And another thing I suggest is having the side you agree with last, not first as in your essay.

So if the essay is "Are computer games good for kids?"  and you think "Yes, computer games are great!" you might use this layout:

• Intro
• Some people criticize computer games because...
• But I agree with having lots of games for children because...
• Conclusion

But if the essay is "Are computer games good for kids?"  and you think "No, computer games are the work of the devil!" you might use this layout:

• Intro
• Some people think games are useful and teach children useful skills..
• But I think computer games should be banned because...
• Conclusion

Again, this is not a requirement - it's just a common layout. Put the side you agree with in Paragraph 3.

1) First of all, I think that some is the same of someone or some people, right ?

To be honest, i'm not quite sure whether using some to represent people is correct or not. But I prefer to say directly "some people"

2) In this essay, my teacher require me analyse two sides of playing computer games, and i think that playing computers games harm children more than help them that why i analyse the first path in Body too much, so that the length of the two body paragraphs is not equal. I think it is simple, but through your comment, i'm afraid that it not be encouraged in Essay, is it?

Personally, I think the way you approach this essay might be suitable for the argumentative essay. For example, if the question ask you "to what extent do you agree or disagree ?" or "What is your opinion ?", then the way you presented is fine. However, this question ask you "Discuss both view?" so it might be better if you give the same amount of ideas for both sides. 

Hope that helps! You can ask me more if you are still unsure.

First of all, I think that some is the same of someone or some people, right ?

In this essay, my teacher require me analyse two sides of playing computer games, and i think that playing computers games harm children more than help them that why i analyse the first path in Body too much, so that the length of the two body paragraphs is not equal. I think it is simple, but through your comment, i'm afraid that it not be encouraged in Essay, is it?

Anyway, Thanks very much.Thanks to your correction my grammatical mistakes, I will improve my grammar too much.

Thankfully!

Here is my comments about your essay:

Overall, I think you include relevant ideas to answer this question. However, I want to mention about negative points:

1) Introduction

I think you'd better give your opinion saying that which side you agree with. Your thesis sentence did not give your opinion.

2) Body

The length of the two body paragraphs is not equal. This first one is much longer. It might be better of you included the same number of ideas for each side. 

3) Conclusion

You should not include new ideas in your conclusion. Basically, your conclusion should only restate your opinion and summarize the information. Here you mentioned about the solutions which are irrelevant.

I've just edited some of your grammatical mistakes below :

"Nowadays, when society develop day by day, children have many chances to contact with advanced technology products (utilize advanced technology products). The use of computer with many kinds of games is a specific example. Some people think they are dangerous for children in every ways; others think (argue) that they help children's development.In this essay I will analyse how does computer games affect to children.

    On the one hand, computer games hamper children's growth. Spending too much time on computer games may leads to health problems.Young people today seem to think nothing of (ignore) protect health (health protection).They can spare (spend) time to play (playing) games all days instead of taking some sports or outdoor activities. I think children will have important consequences about (experience) health problems such as eye strain leads to short sightedness, backache, obesity or even addiction.There are many cases which children steal money, even kill friends or parents due to addicted to play games but out of money. Moreover, children be involved in games excessively may leads to ignore study, skip classes, experience poor academic performance … and so on. They will serious affect to children's future. Playing games too much children can't develop social interaction. Children not socialize with human beings but machine, not express feeling and emotion and not use body languages.

    On the other hand, I can't deny several benefits which computer games bring to children. Through (By) playing computer games, children can learn how to use computer such keyboard, software…It will be more profitable for children to develop intelligence, logical thinking…It is very useful for children's studying especially Math subject (to study math). Moreover, playing computer games can reduce stress, improve mental heath after stressful studying or working.

    In my opinion, an obsession with computer games is not good for children. I think that parents should encourage children for playing (to play) games which is useful for children's development, and strictly forbid all violence or dissolute games. Beside that, parents have to control closely about time of playing computer games of children. If children can assign suitable time between playing games and studying or playing sport, they can have a total development, both the body and the mind."

Full topic:"Some think that computer games are dangerous for children in every way; others think that computer games help children’s development. Discuss both views and give your opinion"

    Nowadays, when society develop day by day, children have many chance to contact with advanced technology products. Computer with many kinds of games is a specific example.Some think they are dangerous for children in every ways; other think that they help children's development.In this essay I will analyse how does computer games affect to children.

    On the one hand, computer games hamper children's growth. Spending too much time on computer games may leads to health problems.Young people today seem to think nothing of protect health.They can spare time to play games all days instead of take some sports or outdoor activities. I think children will have important consequences about health problems such eye strain leads to short-sight, backache, obesity or even addiction.There are many cases children steal money, even kill friends or parent due to addicted to play games but out of money. Moreover, children be involved in games excessively may leads to ignore study, skip classes, experience poor academic performance...and so on. They will serious affect to children's future. Playing games too much children can't develop social interaction. Children not socialize with human beings but machine, not express feeling and emotion and not use body languages.

    On the other hand, I can't deny several benefits which computer games bring to children. Through playing computer games, children can learn how to use computer such keyboard, software...It will be more profitable for children to develop intelligence, logical thinking...It is very useful for children's studying especially Math subject. Moreover, playing computer games can reduce stress, improve mental heath after stressful studying or working.

    In my opinion, an obsession with computer games is not good for children. I think that parent should encourage children for playing games which useful for children's development, and strictly forbid all violence or dissolute games. Beside that, parent have to control closely about time of playing computer games of children. If children can assign suitable time between playing games and studying or playing sport, they can have a total development, both the body and the mind.