We are excited to announce the availability of Encrypted AMI sharing across accounts in AWS China (Beijing) Region operated by Sinnet, and AWS China (Ningxia) Region operated by NWCD. 

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/06/encrypted-amazon-machine-images-sharing-across-accounts-available-aws-china-beijing-sinnet-ningxia-nwcd/