If you're looking to fly from Beijing Capital Int. At the moment, there are zero airlines flying to Seoul. Go through the results to find the right flights for you – you can adjust the filters to see find even more flights to Seoul.
Airport to Seoul. If you want to broaden your search, look at flights departing from other airports.
Your flight from Beijing Capital Int. Take a look at flight times to see which one works best for you.
You can also search by month, which will reveal the cheapest time of the week to fly.