Can I use Adobe software in mainland China, which was bought in Hong Kong?

Maybe @Vivek12 could be of help here.

Don't think so - I've bought mine in Poland - there was a 40% promo more than a year ago - but I live in the UK. 

As long as Adobe is able to bill you and get paid - don't think it matters where you live.

That's an interesting question, and I am sure there are users here who have specific knowledge... assuming it's up to date, as these things tend to change day by day.

My guess (semi-educated, no more) would be that the software will continue to work as long as the licensing remains valid, which I believe is 30 days from the last valid activation-server ping. Whether that activation can be reached through the Great Firewall or not, I have no idea. I wouldn't count on it. As for the limits of VPNs, I would guess you or some colleague on the ground there would know best.

Nor would I count on having reliable access to the online Adobe resources like stock and fonts.

But, hey, it's Sunday. The situation could change on Monday. 😛