Originally Posted by
dvs7310
US Passport holders have been able to transit without a visa in China for many years now as long as the transit has been to a 3rd country, (eg. not US-China-US). You've also been allowed to leave the airport at Shanghai for quite some time, and now that has been extended to PEK, CAN, and other points as well as long as your next flight is within 24 hours.
for PVG it's 48 hours for US Passport holders and 24 hours in PEK TWOV (transit without visa).