Analysts on the mainland said the move showed that despite increasingly strained ties with the US, China still wanted to forge closer ties with the American military.
It is the first time that the PLA will take part in the Rim of the Pacific naval drills.
"The drills will show China's willingness to cooperate with the US amid their inevitable competition in the Asia Pacific region," said Li Jie , a Beijing-based naval expert.
Four ships from the PLA Navy have embarked from Sanya on Hainan Island and Zhoushan in Zhejiang province.
The fleet includes the navy's fastest and most advanced 4,000-tonne missile destroyer Haikou, the missile frigate Yueyang, the supply ship Qiandaohu, the hospital ship Peace Ark, two helicopters, a commando squad and a team of divers.
About 1,100 navy personnel will take part in the drills later this month.
The PLA Navy's presence during the exercises, known as Rimpac, showed that quarrels with the US over China's territorial ambitions in the East and South China Seas would not halt military exchanges with Washington, said Shanghai-based military observer Ni Lexiong.
"China could use this time to observe how the US Navy commands and coordinates its allies like Japan and the Philippines and to get data about US naval bases in the Asia-Pacific region, which will become useful intelligence in case the two countries have a maritime standoff or conflict in the future."
US Defence Secretary Chuck Hagel said at a regional forum last month that China was destabilising the region by pressing its claims in the South China Sea.
His comments came amid a series of clashes between Chinese and Vietnamese vessels after China set up an oil rig off the disputed Paracel Islands.
The Rim of the Pacific naval exercises are scheduled to run from June 26 to August 1.
The PLA flotilla will join vessels from Singapore, Brunei and a US cruiser in waters off Guam in the middle of the month and then sail to Pearl Harbour in formation.
This year's drills, which involves 23 countries, will be led by the US with support from Australian and Japanese commanders.
The website of Rimpac 2014 said the PLA Navy would take part in drills including live-fire exercises, warship drills, military medical exchanges and diving exercises.