The benchmark Korea Composite Stock Price Index added 2.89 points, or 0.12 percent, to 2,363.07 in the first 15 minutes of trading.
On Wednesday (local time), US stocks closed at fresh record highs, with the S&P 500 inching up 0.1 percent and the Dow gaining 0.2 percent.
Most large caps on the Seoul bourse traded mixed, with tech shares leading the gain.
Market bellwether Samsung Electronics added 0.85 percent, and global chipmaker SK hynix was up 0.53 percent.
The local currency was trading at 1,132.2 won against the US dollar, down 3.7 won from the previous session's close. (Yonhap)