Wait 2 or 3 days after she has left, then send her a short message saying that you're thinking of her, that you hope she's having a good time, and that you'll be very happy to talk to her when she gets back. 

Even though a romantic gesture like a song or a long letter will certainly make her giddy (she's a 21 year old Chinese girl, there is not a more hopelessly romantic wilting flower in the world), it's best not to play your cards too early.  I'm sure she sees the possibility of a romantic relationship with you (and you with her), but wait until you know more about her until you sweep her off her feet.

If you live in China, the possibility is a lot higher.  If not, it's hard to say, since she's only 21 and a long-distance relationship with someone she hasn't met face to face probably isn't enough to keep her satisfied for long.  If you see something start to develop, you're going to have to make the trip to China.

Good luck bro.

Thanks again for your advice.  She came back and we are talking.  I didn't do anything dramatic, I just sent her a small mail and she talked to me online the night that she got back.  

Now I want to tell her how I feel.  Should I do this?  Should I tell her that I care about her and I am developing feelings for her even though we have never met?  

I really believe that she is the most beautiful and interesting girl ever, should i tell her this??

Please help!  Thank you very much!

Only a piss-stained loser vomits out his undying love for a girl he hasn't met in real life and only knows 3 weeks.  It sub-communicates to the girl that you are very inexperienced which to many women is like catching a glimpse of a dogs -beep-.  Even a hopelessly romantic, giddy 21 year old Chinese girl can smell weakness off a man and although he may get away with it there is also the possibility that she will lose her hard on.  Not worth the risk.

You've met a girl you like and that's awesome.  Now you don't want to -beep- it up and you are looking for advise, smart.  Just put the gayness down and step back from the ledge.  Keep her guessing about your feelings for her and let the tension build.  You are the man and you must lead the relationship.  That means keeping your emotions in check, playing it cool and never, ever telling her that you love her until you are sure she has committed to you. 

You can communicate how you feel with little acts of kindness and thoughtfulness.  If she asks her directly if you love her, make a joke out of it and tell her that she is moving up the ranks and may make it someday if she ………fill in the blanks (learns how to cook a jelly custard, knits you a sweater for your dog back home or some other ridiculous task).  Keep it light and humourous at the beginning.  Same goes if she asks you if she is beautiful.  Make a joke of it.  Don't directly answer yes until you have kissed her.  Even then it is a bad idea to jump through the hoops she sets up for you.

Men usually fall in love first.  Women are more calculating because the stakes are higher from them.   Have high standards.  Get to know the girls qualities other than how she looks.  Not so easy when dealing with a Chinese girl as half the things she tells you may not be accurate.  Make sure she is not a scammer.  Where does she work?  How much does she earn?  Does she have any tattoos?  Does she smoke?  Does she drink?  Use her email to search if she is online on QQ or some other site/blog.  How many friends does she have – the more she has the worse it is.  Is she a party girl?  Many shots of her at the club?  If she smokes, has a tattoo, lots of "friends" on line and is frequently in clubs, odds are she has soaked coke for mohnee at some point unless she is a model or a big city (Beijing, Shanghai, Shenzhen-born) or wealthy girl.

Because of the cultural difference, many foreigners project their own fantasies onto young Chinese women who are a bit of a blank slate compared to white women.    You end up deeply in love with a girl with whom you have nothing in common except sexual attraction.  Meanwhile, you fool yourself into thinking that you are soul mates because she gives you an erection a cat couldn't scratch.  

There are probably 10 million Chinese women on-line that could be a potential match for you.