It has been a rare good week for Australia's China-based diplomats.

Not only has Trade Minister Simon Birmingham made his first official visit to Shanghai, but Foreign Minister Marise Payne also announced she would visit Beijing, breaking a year-long ministerial freeze imposed by China's Government.

Such regular trips by high-profile ministers were once common, but they have been delayed, scuttled or scaled down over the past two years as China's anger over allegations of Communist Party influence in Australia resulted in an unofficial policy to put Australia in the doghouse.

Diplomats have had to bear the brunt of regular reminders from Chinese counterparts that Australia must "correct" its behaviour.

The media has come in for special attention from Chinese authorities, with the ABC website blocked for allegedly breaching the country's very broad censorship laws.

At least one Chinese company had recently been ordered to hold off on announcing fresh investment in Australia, according to a Beijing-based Australian business source.

All up, it has been a fairly chilly time to be an Australian in the Chinese capital.

So it is understandable — the excitement in official circles around what would normally be a routine bi-annual visit by a foreign minister this week.

Both in China's official media and through Australian business circles, the reason for the diplomatic thaw is clear — Beijing is satisfied Australia's Government is no longer publicly naming and blaming China in the way former PM Malcolm Turnbull did during the peak of the debate around new foreign interference laws.

That is not to say all the differences over political values, the South China Sea and China's expansive foreign policy have disappeared — indeed Mr Birmingham acknowledged as much in Shanghai this week.

But in the face of a tough trade battle with the US, China now appears willing to put those differences aside.

Australian businesses to benefit

Australian businesses are relieved, even though few have seen any tangible trading drop-off as a result of the diplomatic spat.

Two-thirds of companies are optimistic about investing more in the Chinese economy, a new survey shows. ( Reuters: Aly Song )

A new survey by the Australia-China Chamber of Commerce in Beijing this week shows two-thirds of companies are optimistic about investing more in the Chinese economy, even though it is slowing down.

Companies like Swiss, Blackmores, A2 Milk and Freedom Foods have all been buoyed by President Xi Jinping's fresh pledge to boost imports into the vast Chinese market.

Australian medical companies and education providers are welcoming promises to lift foreign equity caps for those sectors in China.

Critics point out Chinese leaders have a history of promising more openness while maintaining the most protectionist domestic market of any major economy.

But Xi Jinping went to an awful lot of trouble to create this week's massive Import Expo in Shanghai and was at pains to stress China would continue to open up.

If he actually follows through, Australian businesses must feel a little more confident now they are in a position to capitalise on it.