shanghai 2 days and kunming in airport

i am in shanghai 25th nov at 15.45, i leave shanghai 27th nov 21.00. from there i fly to kunming and arrive 00.40 on the 28th nov, and leave 14.25 the same day. all together i am in china for 71 hours, i do not intend to go out of the airport at kunming, do i need a visa?