The answer to this is yes and no. Even though there is an insignificant % of Christians in China they still do celebrate Christmas, but not as a religious holiday where people go to mass or anything. Though TBH I wonder how many British Christians or those who consider themselves Christians go to mass or church services.
Note TCG is not of any religion I narrowly dodged a baptism though. Baptisms are dangerous as I have one of those faces you want to push under water and hold it there until I stop moving.
This was when pastors used that old pressure tactic on you.
The olde' stand up and let Jesus into your heart! pressure sales tactic.
Anyway I digress back on topic...
It is observed more as a commercial holiday. Where green, or rather red is spent in moderate quantities. Like how we see Valentines day kinda, where peer pressure and face means you HAVE to buy people stuff to save and give face. You see Santa's grotto's, Christmas trees and people dressed up in Santa costumes even in Mainland China. Which is pretty easy because 100% of this plastic tat is made in China. Though there are also differences in the decorations too. As you get lots of red things and lots of paper lanterns and much less of the fake snow. Though this is perhaps understandable in Beijing and northern China as they have tons of knee deep snow. Much like I am experiencing in the UK right now.
However the celebrating is not universal even in the big cities, some people are cynical like me and simply scoff at the suggestion. My dad for instance scoffs at the suggestion and on Dec 25th 2008 I remember seeing his photos of him playing mahjong instead of doing anything religious. Outside the big cities it can be completely unheard of and no effort made to celebrate the religious or commercial aspects at all. Unless say a bunch of westerners happen to be visiting.
What sort of drags it down is that New Years (Chinese and the Gregorian one) is so close by. Much like Thanks giving in the USA is overshadowed by Christmas.
TBH i think Children love to celebrate Christmas in China because it is yet ANOTHER opportunity for extortion where there is expectant demand for little red envelopes.
In the SAR's it is celebrated as we do in western nations due to western influence and it is a official holiday.