The benchmark Korea Composite Stock Price Index (Kospi) rose 10.42 points, or 0.33 percent, to close at 3,140.51 points.
Trading volume was moderate at about 575 million shares worth some 14.6 trillion won ($12.4 billion), with losers outnumbering gainers 491 to 380.
Foreigners bought a net 46 billion won, while institutions sold 306 billion won. Retail investors purchased a net 223 billion won.
The key stock index got off to a weak start as investors digested mixed US economic indicators, such as strong retail sales in August and their impact on the global economy.
South Korean stock markets are closed Monday to Wednesday for the Chuseok holiday, the Korean equivalent of Thanksgiving.
Market kingpin Samsung Electronics gained 1.45 percent to 77,200 won, and No. 2 chipmaker SK hynix added 2.88 percent to 107,000 won.
Internet portal giant Naver increased 0.25 percent to 403,000 won, with top pharmaceutical firm Samsung Biologics moving up 1.86 percent to 933,000 won.
Leading carmaker Hyundai Motor climbed 0.48 percent to 209,000 won, while giant chemical maker LG Chem retreated 2.09 percent to 701,000 won.
The local currency closed at 1,175 won to the US dollar, down 3.2 won from the previous session's close.
Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys rose 2.5 basis points to 1.535 percent, and the return on the benchmark five-year government bond added 2.8 basis points to 1.790 percent. (Yonhap)