The benchmark Korea Composite Stock Price Index (Kospi) rose 4.09 points, or 0.13 percent, to 3,152.92 points in the first 15 minutes of trading.
Bio and bank gains led the Kospi's rise, while chemical and auto shares got off to a weak start.
Market kingpin Samsung Electronics added 0.26 percent, but No. 2 chipmaker SK hynix retreated 1.4 percent.
Internet portal operator Naver increased 1.61 percent, and pharmaceutical giant Samsung Biologics gained 2.3 percent.
Top automaker Hyundai Motor declined 0.24 percent, and leading chemical firm LG Chem dipped 3 percent.
The local currency was trading at 1,172.7 won to the US dollar, down 1.9 won from the previous session's close. (Yonhap)