Are there nonstop flights from Sapporo (CTS) to Changsha (CSX)?

No. The fastest connection is via Seoul, about 4h 33m of total flying time.

What is the fastest connection from Sapporo (CTS) to Changsha (CSX)?

via Seoul ≈ 4h 33m, via Shanghai ≈ 4h 37m, via Dalian ≈ 4h 43m (estimated flying time, excluding layovers).

from 11,500 ANA miles, from 15,000 JAL miles (economy, one way, based on the published award charts).

New Chitose Airport (CTS) to Changsha Huanghua International Airport (CSX)・3,023 km

No nonstop flights. The fastest connection is via Seoul (ICN), about 4h 33m of flying time (layover not included).

With milesANA 11,500 miles+ (via ICN)JAL 15,000 miles+ (via ICN)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

7 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.