The benchmark Korea Composite Stock Price Index added 8.41 points, or 0.35 percent, to close at 2,386.07. Trade volume was slim at 290 million shares worth 6.1 trillion won ($5.2 billion), with gainers slightly outnumbering losers 406 to 403.
The Seoul index hand opened lower after North Korea fired another ballistic missile earlier in the day, after the United Nations Security Council adopted a fresh sanctions resolution against the communist state.
"The local stocks market started lower affected by North Korea's missile launch but soon gained ground as investors picked up some market heavyweights," said Lee Yeong-gon, a Hana Financial Investment analyst.
Large caps on the Seoul bourse closed mixed, with telecoms and tech shares leading the gain.
Tech shares ended higher, with top cap Samsung Electronics adding 0.2 percent to close at 2,521,000 won and its smaller rival LG Electronics adding 1.82 percent to 89,500 won.
SK hynix, a major chipmaker, advanced 0.52 percent to extend its winning streak to six days, closing at a record high of 75,700 won.
Mobile carriers closed in positive terrain, with No. 1 player SK Telecom jumping 4.55 percent to 253,000 won and second-largest KT moving up 1.03 percent to 29,400 won. LG Uplus, the smallest in the country, added 1.11 percent to 13,700 won.
Auto stocks closed mixed, with leading automaker Hyundai Motor losing 0.36 percent to 136,500 won and its sister company, Kia Motors, adding 0.98 percent to 30,900 won. Auto parts maker Hyundai Mobis increased 1.17 percent to 216,000 won.
Shares of biopharmaceutical firm Celltrion soared 6.86 percent to close at a record high of 127,700 won after sales for Herzuma, the treatment of metastatic breast cancer, began.
The local currency closed at 1,131.7 won against the US dollar, up 0.9 won from Thursday's close.
Bond prices, which move inversely to yields, ended mixed. The yield on three-year Treasurys fell 0.3 basis point to 1.739 percent and the return on the benchmark five-year government bonds added 0.4 basis point to 1.949 percent. (Yonhap)