Grace and Sterne will attempt to become the fifth South African team to win the World Cup.
Past South African winners are Gary Player and Harold Henning in 1965, Bobby Cole and Dale Hayes in 1974, Ernie Els and Wayne Westner on home soil at Erinvale in 1996, and Els and Retief Goosen in 2001.
With South Africa’s other top-ranked players Charl Schwartzel, Els and Louis Oosthuizen not available, Grace and Sterne join a 60-player field.
The winners will be determined over 72 holes of stroke play, competing for approximately R70 million ($7 million) of the R80 million ($8 million) total purse.
The players from each country will compete for the team portion, using combined stroke play scores.
The individual portion is similar to what will be used at the 2016 Rio Olympics, except that England, Scotland, and Wales will have teams instead of a single Great Britain team in the Olympics.
Defending champions the United States won the title in China in 2011 at the Mission Hills Resort on Hainan Island with Matt Kuchar and Gary Woodland representing them.
Kuchar returns to the event in 2013, with his number eight world ranking securing his spot at the event.
Grace will be playing the event for the first time, while Sterne has represented South Africa three times in 2006, 2008 and 2009.
Between them, they have won 10 times on the Sunshine Tour, with Sterne taking the 2008 South African Open Championship.
Grace won four times on the European Tour last year, and lost in a play-off to Phil Mickelson in this year’s Scottish Open, a week before Mickelson went on to win The Open Championship.
Sterne took the 2013 Joburg Open on the European Tour ahead of 2011 Masters champion Charl Schwartzel.