A nice song, by 宇恒，幸雁，戴丽金 and William. I searched this song, but very hard to search. And finally found it, but in .flv format.
If you like it, you can download. Do you know the trick to download?
And if you want to convert to mp3, you can use FormatFactory. And just convert the .flv file to mp3, it is okay.
Pazera Free Audio Extractor is also another good choice.