Shenzhen Airlines will buy 46 Boeing 737 planes in a deal worth U.S.$4.3 billion at list prices, its parent company Air China said in a statement on Wednesday.
China is already Asia's biggest aircraft buyer, as a growing middle class takes to the skies in ever-increasing numbers.
The airline will take delivery of the planes from 2016 to 2020, said the statement to the Shanghai Stock Exchange, where Air China is listed.
The airline owns over 100 passenger and cargo aircraft including Boeing 747s and 737s, as well as Airbus A320s and A319s.