China Eastern plans to use the long-haul planes for travelling between China, North America and Europe, Boeing said.
We are very happy to introduce the new 787 Dreamliners into our long-haul fleet," said China Eastern Airlines Chairman Liu Shaoyong in a statement.
"The addition of these next-generation, fuel-efficient airplanes will play a key role in supporting China Eastern's strategy for international expansion, and enable us to realize profits in point-to-point routes across the Pacific Ocean, and between China and Europe."
China Eastern is one of China's top three airlines, operating 560 aircraft and carrying around 100 million passengers annually.
The order comes one day after Boeing reported an 8.8 percent drop in first quarter earnings to $1.2 billion, partly due to slower aircraft deliveries into a slowing global economy.