Flying from China to S.Korea

The question is too vague. Where in China to where in Korea. When? You really ought to check out some travel websites and search for flights.

Here's information on ferries:

http://visitkorea.or.kr/ena/GK/GK_EN_2_3_2.jsp

You can use the foreign language help with Korea tourism if you can't communicate with them.

Do you know how much a cheap flight can cost between the two countries?

It depends from where in China (and to where in South Korea) you want to fly.

Of course...

From Beijing to Incheon or Gimpo, if there are cheaper destination within Korea it's also ok.

Ferries from WeiWei or Tianjin to Incheon. I don't know if there are other options from China.

thanks.

When?

Not to be snarky, but is there a reason you ask here instead of searching a travel website? Prices fluctuate so much.

There aren't low cost airlines with direct flights on that route (Beijing-Seoul) so any search engine of flight fares (e.g.: Skyscanner, Kayak...) will tell you what's the cheapest option on your travel dates.

I would recommend using Skyscanner . You can even just put in a country to begin with and then see all the options. Some of the Chinese airlines have cheap flights into Incheon, might be worth looking at them.

i checked several sites,

but didn't got cheap rates...

I might travel to Mongolia from Seoul... I wanted to travel there by land from Beijing, and after Mongolia and Beijing to travel in Korea.

thanks

I might travel to Mongolia from Seoul...

MIAT and Korean Air have direct flights on that route. Air China changing planes in Beijing could be another option. Don't expect a bargain though!

You should have a look at www.ctrip.com or the official website of China Eastern Airlines. There are good value flights.