The Sapporo Sightseeing Guide provides a good overview on access to Sapporo from overseas and access from Chitose Airport (CTS) to central Sapporo. Sapporo Sightseeing Guide
We expect most overseas participants will use Narita Airport (NRT) as their airport of entry into Japan. Please note that connecting flights from Narita are limited to four flights/day. The NRT/CTS connecting flight may not meet your arrival schedule and may be difficult to book from overseas.
As such, for attendees arriving at Narita (NRT) Airport, we recommend you take the bus to Haneda Airport (HND) - the domestic airport in Tokyo and connect to Chitose from there. Narita-Haneda Bus Timetable (75 min. / 3,000 JPY).
There are more than 60 daily return flights connecting HND/CTS.
The Chitose Airport site provides a very good search tool showing all flights to and from the airport.
Sapporo can also be accessed directly from Kansai International Airport (KIX) in Osaka (8 daily connecting flights to Sapporo) and Chubu International Airport (NGO) in Nagoya (11 daily connecting flights to Sapporo). This option may be preferrable for European attendees in particular.
Finally for Asian attendees, please note there are direct flights to Sapporo from Shanghai, Seoul, Taipei and Hong Kong.