The company did not say how much it was paying, but the average price of the aircraft on January 30 was about $80 million (57 million euros).
This would point to an overall catalogue value of about $2.4 billion. A bulk order however, would normally involve a discount.
"The current order is timely as the aviation industry has returned to profitability and airlines are looking to add capacity," Robert Martin, BOC Aviation chief executive, said.
The company said it would shortly announce its decision on the engines to be used in the aircraft.
The latest order brings to 128 the number of aircraft in the A320 family that the company has ordered, 80 of which have been delivered, it added.
"In the last three years, we successfully doubled the size of our fleet and have over 160 aircraft as of today." Martin said.
BOC Aviation is 100-per cent owned by Bank of China.
What the stars mean:
★ Poor ★ ★ Promising ★★★ Good ★★★★ Very good ★★★★★ Exceptional