Three navy ships from the Chinese People's Liberation Army will spend the next four days docked in Sydney.

The ships are arriving in Sydney this morning for a brief stop-over on the way to China.

They are returning from a mission to combat pirate activities in the Gulf of Aden between Yemen and the Horn of Africa.

Defence Minister Stephen Smith says China has a central role to play in maintaining regional security.

He says both navies will share lessons learnt about anti-piracy operations during the four-day visit.

The stop-over is one of a number of events planned this year to mark 40 years since the beginning of diplomatic relations between Australia and China.

In May the HMAS Ballarat visited Shanghai to carry out an exercise with a Chinese navy frigate at the mouth of the Yangtze River.