The benchmark Korea Composite Stock Price Index (Kospi) rose 9.33 points, or 0.32 percent, to 2,968.79 points in the first 15 minutes of trading.
The key stock index got off to a strong start after overnight Wall Street gains, as a temporary resolution of the debt-ceiling tussle is due for a vote in Washington.
Overnight, the tech-heavy Nasdaq composite advanced 1.05 percent, and the S&P 500 moved up 0.83 percent. The Dow Jones Industrial Average climbed 0.98 percent.
Expectations of strong third-quarter corporate earnings also boosted the investor sentiment, as KOSPI's top cap Samsung Electronics Co. is expected to post record sales in the third quarter, apparently buoyed by its semiconductor business.
Samsung Electronics edged up 0.14 percent, but No. 2 chipmaker SK hynix retreated 0.73 percent.
Internet portal operator Naver retreated 0.38 percent, but pharmaceutical giant Samsung Biologics added 0.49 percent.
Top automaker Hyundai Motor increased 2.24 percent, and leading chemical firm LG Chem gained 1.63 percent.
The local currency was trading at 1,192.45 won to the US dollar, down 2.05 won from the previous session's close. (Yonhap)