The move comes as airlines in China benefit from a boom in domestic and international air trips as the country's middle class spends more on travel and leisure.
It will also come as a boost to European giant Airbus, which is competing heavily with US rival Boeing in China, the world's second aircraft market.
The US company has forecast China needs more than 7,200 commercial aircraft in the next 20 years, while the International Air Transport Association predicts the country will overtake the US as the world's largest air-travel market by 2024.
The country's three biggest carriers -- Air China, China Eastern and China Southern intend to increase their fleets by more than 600 aircraft in total within the next three years.
CALC chief executive Mike Poon said: "We are proud to augment our fleet by adding 50 in-demand A320neo jetliners that have outstanding fuel efficiency, and are reliable and comfortable.
"Since CALC's inception, we have maintained a close and dynamic relationship with Airbus, and the commitment marks yet another endorsement of our mutual trust.
"This bulk purchase will significantly expand CALC's fleet portfolio and further solidify our position as a full value-chain aircraft solutions provider."
The statement from CALC said the announcement takes its total orders with Airbus to 202 aircraft, adding it would "purchase 15 additional Airbus A320neo aircraft in January 2018 subject to the fulfillment of certain conditions".
The firm, which also has 50 jets on order from US giant Boeing, currently has 102 aircraft.
The firm's shares were up 2.0 percent at HK$8.17 by the break in Hong Kong trade.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)