Australian Minister for Communications Malcolm Turnbull has reminded fellow Australians of China's vital role fighting against Japanese forces during the World Word Two, saying it should not be forgotten that China was Australia's "longest ally".

"In this year of 70th anniversary of the end of World War II, it is important not to forget that in Australia's battle for survival against Japan our longest ally was China itself," Xinhua quoted Turnbull as saying.

He mentioned that August 6 this year marks the 70th anniversary of the atomic bomb being dropped on Hiroshima followed two days later by another atomic bomb on Nagasaki. A week later Japan surrendered and so ended the WWII.

"China had been invaded by Japan in 1937 and fought alone until the attack on Pearl Harbor in 1941," he said.

"Without China's endurance and courage in the face of Japan our war history may have ended very differently indeed."

Turnbull said there is a tendency to see the sweep of Chinese Australian history solely through the prism of the cold war and then the opening up of China and the economic development that followed.

"We should never forget that the history of our two nations is long, rich and complex," said the minister.

"We could not imagine modern Australia without China's contribution to our people, our culture, our prosperity."