Hi Cindy,

If you wanna host in mainland China, yes you will need ICP, but only doable by Chinese companies or Chinese citizens. If you already have a domain, you can transfer it to your new Chinese host though still, you need to get a Chinese company or Chinese citizen to obtain the ICP license then you will be able to host in mainland China.

ICP usually is applied via your Chinese hosting company, not on Baidu, not on MIIT directly.