SA's largest ever China trade mission

South Australian Premier Jay Weatherill and executives from more than 100 businesses have left for the state's largest ever trade mission to China.

Their departure coincides with the 30th anniversary of SA's sister-state relationship with the province of Shandong.

"To get ahead in a competitive world, we need to build South Australia's international connections, alliances and exports to a new level - our future prosperity depends on it," Mr Weatherill said on Monday.