Hi Sara

Thanks for this essay. It's OK – not very exciting. Perhaps a few examples from your experience would make it more interesting. 

Generalizations

Be careful to avoid simplistic generalizations. It is fairly unlikely that tourism could lead to a world war (paragraph 3) or that by simply visiting a country we can learn about advanced technology. Generalizations might limit you to a Band 7 (see http://www.ielts.org/pdf/UOBDs_WritingT2.pdf under Task Response).

A few small points: 

The first key [pick one] answer to the above [avoid: keep your writing going forward -  don't make the reader go backward] question is, the international globalisation. Men [Only men? What about women? Children?] get opportunities to understand the native culture; local cuisines, dressing manners [dress], and different languages. Additionally, the relationship between the locals and the foriegners becomes healthy. [How? This point is not fully developed] Thus, people from rich countries [Generalization: why only people from rich countries? What about rich tourists from China or India?] understand and donate [wrong word - omit?] the under-developed nations. Moreover, visitors gain knowledge in advanced technologies by travelling to many developed countries. [Generalization: can we really understand technology from a one week visit to a country?] As a result, there is an exchange of culture, aids, aid technologies by promoting brotherhoodness between nations.

What is the question in the first sentence in this paragraph? How does international globalization improve communication? The question in your intro paragraph is a Yes/No question. 

Perhaps this would be a more developed version:

Tourism can indeed improve communication, understanding, and friendship. Travelers experience the local culture with its cuisine, clothes and languages. They have an opportunity to meet the local people and become friends: what was unknown or even frightening becomes exotic and interesting. Traveling to developed countries may help spread new technology at home, while traveling to poorer countries may remind the tourist of deeper ways of thinking.

There are some comma splices and run-on sentences as well as unncessary commas in the essay:

• This is illustrated by an example, Africans are sometimes ill-treated in the western countries. 
• The first key answer to the above question is, the international globalisation

Your opinion is given clearly, and your conclusion is also clear. Just watch out for some unclear references, some verb agreement errors, some missing articles, and be careful to avoid generalizations.