But health drinks have surged, with sales of green tea products more than doubling to 50 billion won (US$49.1m), sources told Yonhap news.
Sales of functional drinks also jumped 25 per cent while mineral water sales increased by 5 per cent.
Overall the industry's annual sales dropped to 3.4 trillion won ($3.3bn) this year, according to the report, with soft drinks down 7 per cent to 1.8 trillion won ($1.7 bn).
Coca-Cola sales alone were 450 billion won, a 10 per cent decrease on the prior year, and juice, coffee, sports drinks, soy milk and traditional drinks, also saw declines of up to 10 per cent.
Sales of beverages containing grain extracts plunged 40 per cent.