Thursday's Airbus sale was among a series of business deals signed as the French president, Jacques Chirac, began a state visit to China.
The order would be worth over $10 billion at list prices, but such large purchases usually receive deep discounts.
The final assembly line, in the eastern Chinese city of Tianjin, is Airbus' first outside Europe and was approved by Beijing in June.
"With a big country like China, if you want to be present (commercially), you also need to be present industrially," said Louis Gallois, the Airbus chief executive.
China, which often maintains a balance between rivals Airbus and Boeing, bought 150 Boeing jets during a visit by the US President, George Bush, in November 2005, and another 150 from Airbus a month later.
Airbus, however, hopes to steal a march on its rival on the fast-growing Chinese market by investing in local assembly, even as it faces restructuring at home due to delays to the A380 superjumbo.
China also signed a letter of intent to purchase 20 of Airbus's planned larger A350, which is still on the drawing board, although a final decision is to be made later.