The C919, with 168 seats and range of 3,444 miles, was displayed at a ceremony attended by 4,000 guests.
The C919's first test flight is not until 2016, but the unveiling was seen as having huge industrial significance.
"A great nation must have its own large commercial aircraft," the country's civil aviation chief Li Jiaxiang said.
"China's air transport industry cannot completely rely on imports," he told the ceremony at a hangar near Shanghai's Pudong International Airport.
The BBC's economics correspondent Andrew Walker says the aircraft represents "an important step in China's economy moving beyond low-cost manufacturing".
The C919's manufacturer, Commercial Aircraft Corp of China (Comac) says it has orders for 517 aircraft from 21 customers, most of them Chinese airlines, but also from leasing company GE Capital Aviation Services
The development of the new aircraft has been hit by delays since the project was conceived in 2008. Assuming the test flights are successful, the C919 is due to enter commercial service in about 2019.
China has had ambitions to build its own civil aircraft industry since the 1970s, when leader Mao Zedong's wife, Jiang Qing, personally backed a project. But the Y-10's heavy weight made it impractical and only three were ever made.
Boeing's latest World Market Outlook puts China's total demand for civilian aircraft over the next two decades at 5,580 planes worth a total of $780bn.
The C919 will compete in the market for single-aisle jets dominated by Airbus A320 and Boeing's 737. But the Chinese aircraft is just the start of a strategy to eat into the Airbus-Boeing duopoly.
Comac also plans a wide-body plane, the C929, in cooperation with Russia's United Aircraft Corp, and the company is also expected to create an aero-engine operation.
A separate state-owned company has developed a smaller regional jet, the ARJ-21, to compete in the market dominated by Brazil's Embraer and Canada's Bombardier. The first two ARJ-21s were delivered last year to a Chinese airline.
Foreign firms are key suppliers to the C919, including Honeywell and Rockwell Collins in the US. The aircraft's engines are made by CFM International, a joint venture between America's General Electric and France's Safran.
China has unveiled its first large passenger aircraft in decades, in an effort to mount a challenge to planemakers Boeing and Airbus.