Four artillery shells dropped in and around the base compound in Charika, a city in the northern Afghan province of Parwan on Wednesday, according to the South Korean military official.
"Two of the shells appear to have dropped inside the base, with one of them landing outside and the other detonating in midair. We have yet to confirm who was responsible for the attack," he said, adding that there were no injuries or damages to properties.
South Korea has about 90 aid workers and police officers in Afghanistan as its provincial reconstruction team, or PRT.
Some 340 troops are stationed there as members of the "Ashena" unit to protect the team.
This is the sixth such attack on the South Korean base in Charika this year. The official here said the Ashena unit didn't notice any unusual developments around the base after the shells dropped.
It was the first attack on the South Korean base since the death of Osama bin Laden, an al-Qaeda mastermind killed by US forces earlier this week.