The carrier, one of China's "big three" with the largest fleet by size, will take delivery of the A330-300 planes between 2017 and 2019, it said in a statement to the Shanghai stock exchange.
It was the company's second major purchase this month, following a USD 10 billion order for 110 planes from Boeing.
China, the world's second largest economy, is Asia's biggest aircraft buyer as a growing middle class takes to the skies in ever-increasing numbers.
State-owned China Aviation Supplies Holding Group signed a deal with Airbus at the end of October, pledging the purchase of 100 A320 aircraft worth USD 9.7 billion at list prices.