The AVIC AG600 amphibian aircraft conducted its first flight on Sunday 24 December.
The aircraft took off from the Zhuhai airport runway at 09:39 local time and flew for 64 minutes, says AVIC in a statement.
The first flight had originally been planned for 2015, but development issues caused this to be postponed. At Air Show China in November 2016, an AVIC official told FlightGlobal that a first flight was planned in 2017.
The first flight assessed "basic control features." High level officials attended the event, along with workers from the AVIC production hall located near the airport.
China Daily quoted Zhang Shuwei, deputy general manager of China Aviation Industry General Aircraft (CAIGA), as saying that there are 17 orders for the aircraft, all from domestic customers.
The aircraft will serve in parapublic missions such as search and rescue and firefighting. Its maximum take-off weight of 53.5t makes it the world's largest amphibian aircraft, even bigger than the Shinmaywa US-2 at 43t.
In the firefighting role, it can pump 12t of water aboard in just 20 seconds. It can accommodate up to 50 passengers.
AVIC says that the aircraft is very much a product of Chinese industry, with 98% of components sourced locally. This includes its four Dongan WJ-6 turboprop engines.
The effort involved 150 companies and institutions and over 10 universities spread across 20 Chinese provinces and cities.
AVIC adds that the AG600 can take-off in high sea states.
At Air Show China, FlightGlobal learned that the AG600 lacks the boundary layer control system found on Japan's Shinmaywa US-2 amphibian. This device, located between the wings, boosts airflow over the wings, thus improving lift. This is especially useful when the aircraft needs to take off from water in high sea states.