Can we bring our son who is over 18 to China to get a residency visa if we have a residency permit?

He is presently studying in Beijing on a scholarship and would like to continue studying there. We will be going in August and will be getting a work permit. Does he need to get a letter from the university in order to get a Z and residency permit? He is presently in Beijing but is looking for a city with less pollution. We'll be in Guangzhou.