When I want to make an emergency call using my China mobile in US, the best way to call is to use the **139* service.
How it Works
It works this way.
When the China Mobile user is roaming in US, the charge for him/her to call back to China is relatively very high. However, if there is someone in China call his/her mobile, the charge will be at the rate of receiving phone call, and is much lower.
How to Dial
Calling fixed line looks like:
**139*86fixed line number including area code#
It works pretty well.