How bad is the cell reception in China?

My girlfriend wants to visit China and I’m going to be with her during her stay. She wants to go there because of her younger brother who’s gonna be attending some sort of romance singles tour in the country. I don’t have a brother so her brother feels like my own. We’re supposed to be there as his support system, and we’re more than happy to do so.
The only problem I have with this trip is if my phone’s network will be working in China. I’ve used my phone on some overseas trips that I’ve had in the past. But I’ve heard from some friends that they’ve had some problems with the connection during their own stay.
Can I get some feedback if the cell reception in the country is okay and if I would have a problem using my phone? Are there any limitations that I should know about? I really need my internet connection for work.

cell phone reception is the worst i have experienced in any country in the world. be prepared for intermittent and no signal often. most people use land line phones for this reason. at worst during day time and near high buildings