querry change plane

I'm afraid your time is too tight. Generally, you will go through the customs in Nanjing and need to recollect the luggage. However, it is better for you to contact China Southern Airlines to confirm again.

CS service commitment says 60 minutes for transit. I would suggest you to complete visa formalities before flight. You have to go through immigration in GZ airport before taking your transit flight - read international to domestic transfer procedures. Therefore if you need visa to enter China, do so before flight to GZ if not you won't meet the transit time. For your luggage, it's better to reconfirm with CS as your origin airport may not support through luggage, and you may need to pick up and check in your luggage again in GZ thus lengthening your transit time. For rest of mind, check your procedures with China Southern before flying.

thanks
its better i will choose a tension free flight.
thanks for the information

to "Calvin from Singapore" your answer to BijoyPaul worries me. My China Southern flight [next week] from Kathmandu to Beijing has 1h55m "plane change" at Guangzhou - CZ6068 (fr KTM) arr's at T2 and CZ3107 to PEK) dep's fr T2. My paid ticket says "For flight transfers in Guangzhou, baggage can be checked through."
Calvin, do you think that might not actually be true? I might need to claim bags and RE-check them?
Please note: I have U.S. Passport w single-entry Class F Visa and Invitation Letter to a photo festival. I am traveling light. Should I worry? About the TIME? THANKS!