Hey ueirun,
The 2 most outstanding issues right now for your singing are:
1) You are singing by straining your vocal chords and throat
2) Your chinese pronunciation is improper, especially with words that start with the 'S' or 'Sh' sounds.
Someone else already mentioned pitching =)
You can gradually fix number 2 by yourself through READING (note: read, not sing) practice. It's good to get some supervision for the first problem though, if not you may hurt your voice production organs in the long run. Do give me a call if you're interested in singing lessons.
91880920
Vocal coach,
Gary.