Priossing:A window For Me to See the World

Changing postcards to communicate with foreigners makes me a different person. Posetcrossing, an online project that enable its users to send and receive real postcards from all over the world, arouses my curiosity and intrigue to explore the colorful world with open vision. I’m now desiring to express myself and promote Chinese culture to the world and develop myself catering to modernization and globalization and become a world citizen.

Could you please help correct mistakes and polish it up? =) I feel awkward to express my meaning in English.

This is quite good, but there are a few minor changes you can make:

Priossing: A Window for Me to See the World

Exchanging postcards to communicate with foreigners makes me a different person. Posetcrossing, an online project that enables its users to send and receive real postcards from all over the world, arouses my curiosity and intrigues me to explore the colorful world with open eyes. I want to express myself, promote Chinese culture to the world, and develop into becoming a world citizen by catering to modernization and globalization.

-A Window for Me to See the World ("window" should be capitalized, but not "for")
-Exchanging (not "changing")
-enables (not "enable")
-intrigues me (not "intrigue"...This is difficult to explain, but intrigue is better served as a verb here)
-open eyes ("open vision" sounds a bit strange, and "open eyes" is a commonly accepted colloquialism)
-I want to ("I'm now desiring to" is unnecessarily wordy)
-(When listing three or more ideas, you should separate them with commas rather than using "and". "and" should only be used to connect the final two ideas.)
-develop myself into becoming a world citizen by catering to modernization and globalization (To be honest, I was a bit unsure how to rewrite this section. This felt like a run-on sentence, so I modified it to better connect the two ideas. )

For a long piece of writing such as this, I recommend using lang-8, which is designed for receiving reviews on one's writing. Hopefully what I've written helps you, though. :)