The aircraft flew over three Chinese provinces – Guangdong, Hunan and Hubei, the company said, without specifying the start date of tests on water.
The plane has already passed a series of tests since its maiden flight in December.
The AVIC said in mid-May that China expected to deliver the AG600 to customers by 2022.
The aircraft is the largest of its kind not only in China, but also in the world. It is designed to extinguish fires and carry out rescue operations on the water. In addition, AG600 can use additional equipment for monitoring the marine environment, passenger and freight traffic, as well as exploration of mineral deposits.
The aircraft is equipped with four turboprop engines and is able to receive on board 12 tonnes of water in 20 seconds. According to its developer, the state-owned Aviation Industry Corporation of China (AVIC), AG600 has 130-feet-long fuselage, 127-feet wingspan, maximum flight range of 2,800 miles and maximum take-off weight of 53.5 tonnes.