Hello,how long does it take to travel between Hong Kong and Shanghai by Rail? thank you

Well, there is no direct train that operates between these two places. Thus you are suggested to pass the border from Lo Wu and enter Shenzhen first. Then take metro line 1 to Conference & Exhibition Center and line 4 to North Railway Station. After arriving, take direct high-speed train to get to Shanghai Hongqiao Railway Station.
The train schedules are from 07:00 to 20:20. It takes around 12 hours on the way. The ticket fare of second class seat is CNY481 and first class seat is CNY597.

Thank you very much for your comprehensive reply.