Originally Posted by
travelerjim
]
The FREE visa entry is 144 hours in PVG Shanghai...
starts at 12:01am following your arrival.
It is only 72 hours in Beijing PEK
Since the OP's planned stopovers are less than 24 hours, he will be issued 24 hour permits in both cases.
In addition to Beijing, ~10 other cities do the 72 hour thing (for passengers with eligible passports whose planned transits are between 24 and 72 hours).
For more information, see here:
http://www.flyertalk.com/forum/china...er-thread.html