Originally Posted by
jiejie
I don't think you need to worry about booking in advance on this route, as long as you have a little flexibility and can do next-available.
As many of you know, I'm not into advance planning. But, in the case of trains between SH and NJ, HZ, Suzhou/Wuxi, I always like to buy tickets the day before because trains sell out (it's not too hard to get tickets at the station, but Murphy's Law dictates that the most convenient train(s) will not be available).