The benchmark Korea Composite Stock Price Index (KOSPI) fell 16.59 points, or 0.86 percent, to 1,910.16 in the first 15 minutes of trading.
Investors have sold risky assets since Britons voted to leave the EU last week. Instead, the investors bet on safe assets, such as the dollar and the yen.
Analysts expect the global stock markets will remain volatile for the time being, with the country's key stock index likely to flirt with the 1,850-point level.
On Monday, the Dow Jones industrial average dropped 260.51 points, or 1.50 percent, with the tech-heavy NASDAQ dipping 2.41 percent.
Market bellwether Samsung Electronics fell 1.07 percent, top automaker Hyundai Motor Co. dropped 0.35 percent, and the state-run Korea Electric Power slid 0.17 percent.
Among gainers, leading cosmetics maker AmorePacific rose 0.97 percent, dominant tobacco company KT&G climbed 0.39 percent, and leading steelmaker POSCO advanced 0.76 percent.
The local currency was trading at 1,183.95 won against the U.S. dollar, down 1.65 won from the previous session's close. (Yonhap)