If you want to get your master degree in countries other than China, you need to start preparing it now. GPA is vital to your application if you ever want scholarship. That, is something you can't fix later on. So whether you want to do master or not, study hard and keep your GPA above 3.5. There's no time to waste. :D
@money "高中同学", I assume they are doing undergraduate, right? Graduate school has a lot more fundings for master/phd students. Competition in applying graduate school is much more fierce than applying undergraduate, but if you can get the offer, all you need to pay is application fee and flight ticket. If you are interested, dig more info from bbs.gter.net.