Sarkozy and Chinese counterpart Hu Jintao presided over a series of signings following talks at the Great Hall of the People, the hulking legislative seat beside Beijing's Tiananmen Square.
The visit has focused firmly on trade relations, with human rights all but left off the agenda.
China's Foreign Ministry said the big ticket purchases showed how Beijing has worked to reduce its trade surplus with France. Sarkozy has also urged the Communist leadership to let its currency rise in value before trade imbalances become unmanageable.
"China wants balanced trade with its trading partners and the purchases of these airplanes is a sign of how it is striving for that," Foreign Ministry spokesman Liu Jianchao told reporters.
The French leader's gentle approach in China, where concerns linger over the authoritarian communist regime, appeared to be an attempt to put the relationship on a firm footing just six months after Sarkozy's election as a reformer who pledged to stand by "all those who are persecuted by tyrannies, by dictatorships."
In Monday's single biggest agreement, China said it would buy 160 commercial passenger jets from European plane maker Airbus, which is headquartered in France. The deal is worth around $14.8 billion.
The order includes 110 of the company's A320 jets and 50 of the slightly larger A330 planes, Airbus officials said. Airbus and Chinese partners this summer signed an agreement to produce A320s in China in anticipation of large Chinese orders for the popular single-aisle jet that seats 150 or more passengers.
Also, France's state-owned Areva SA finalized a $11.9 billion agreement to sell two nuclear reactors to state-run China Guangdong Nuclear Power Corp. in one of the company's largest contracts ever.
French, American and Russian suppliers have vied intensely for contracts in China, which plans to build as many as 32 nuclear plants by 2020 as it tries to meet surging power demands, while cutting emissions and reducing reliance on imported oil.
While the exact value of the planes wasn't known, French officials speaking on routine condition of anonymity said all contracts - including those for jets and reactors - signed Monday totaled about $29.62 billion.
Despite the heavy commercial bent of his three-day visit, Sarkozy on Sunday urged China to apply the death penalty less frequently, the French presidential Elysee palace said.
Speaking to reporters alongside Hu on Monday, Sarkozy said he appreciated China's progress on improving citizen's rights. However, he said he had also "reiterated France's desire to see further progress, especially in respect to the application of rule of law in the judiciary, the freedom of journalists and in the death penalty."
Paris-based advocacy group Reporters Without Borders had earlier appealed to Sarkozy to raise the cases of 33 journalists and 50 Internet dissidents imprisoned in China.
Sarkozy also addressed the touchy issue of China's currency, the yuan, which many trading partners insist is undervalued, making Chinese products unfairly cheap, allowing it to boost its trade surplus globally.
"We need to arrive at currency rates that are harmonious and fair and that will benefit the global economy. This means that, for its own sake as well, China needs to accelerate the appreciation of the yuan against the euro," Sarkozy said.
Sarkozy warned also of the environmental costs of China's rapid economic growth.
"We hope China's growth can continue, but we also hope China's growth is carbon-free and environmentally friendly. We believe this is in China's interests and the interests of the entire world," he said.
Hu described the talks as "frank" and "friendly" and said Sarkozy had accepted an invitation to attend the opening ceremony for next year's Beijing Summer Olympic Games.
Sarkozy was to meet with Premier Wen Jiabao before flying to the commercial hub of Shanghai on Tuesday, leaving for Paris later the same evening.