Optimizing member areas for Mainland China is actually fairly straightforward. There are really only two things to ensure:
- Don’t use reCaptcha
- Make sure you don’t only rely on 3rd party logins like Google or Facebook (one click login or register) as they might not work in Mainland China
So if you have a normal login and register area with email confirmation users in Mainland China should have no problem signing up and logging into your website.