I went to see a dentist in Beijing and he suggested to apply filling where my Gum is receding. Is that good treatment ad what type of filling is the right one?

If you are having sensitivity then a filling may help. If the tooth is near the front of your mouth a white filling would be ideal, in the back it could be white or silver(amalgam).
Remember though, when fillings are placed near the gumline it makes it more challenging to keep the tooth clean and you can end up with irritation at the gumline.
If the recession is something you can live with then I'd suggest leave well enough alone. What you REALLY need to figure out is, what is causing your gums to recede??