"Not only is this a big hit (2% of all Australian coal imports are destined for Dalian) for the industry but China is also getting tough on Australia after they banned Huawei from their 5G network a year ago", Lien said.
Traders in China maintained the ban was politically motivated.
One analyst in China said Beijing was using Dalian to "test the market" as it sought to wind back Australian imports to boost domestic prices while using it as political leverage at the same time.
Australian officials said there was "confusion" over the situation, and they were consulting their Chinese counterparts.
China is Australia's biggest trading partner and coal is the resources-rich country's most valuable export.
While it was mentioned that the max limit was applicable to all import sources, the port of Dalian has reportedly barred Australian coal imports from entering since the start of February.
Tim Harcourt is the JW Nevile Fellow of Economics UNSW Business School and says China's top supplier of coal is Australia, but now it faces an unexpected and indefinite ban.
"It's not in China's interest to spook the markets, and this may be regarded as just a small shot over the bows of the trade ship", he said.
The Australian sharemarket shrugged off China's surprise Aussie-coal ban and another round of weak global manufacturing data as yield hunting drove buying and the Reserve Bank stuck to its growth outlook.
Australia banned Huawei in August previous year, recently revoked the permanent residency of a Chinese billionaire over concerns that he's an agent of influence and is pressing the Chinese for access to Australian citizens and permanent residents held in prison or trapped in Xinjiang.
This comes after Bloomberg News reported Tuesday that Trump is demanding China commit to keeping the Renmimbi stable, as part of any deal to end the tariff fight between the world's two largest economies.
Some investors linked the restrictions to China's trade war with the US.
"Current inventory at ports should be sufficient to support usage for one or two months, but it could be a problem in the long term, especially if other ports also tighten imports", he said, declining to be named due to company policy.
"We still expect China stocks to outperform on trade hopes and domestic stimulus", Credit Suisse strategists wrote in a daily note to clients. That includes five harbors in the northeastern port of Dalian, according to the people with knowledge of operations there.
"Australia's decision to block Chinese telecommunications giant Huawei from supplying equipment to its 5G broadband network, and allusions by some Australian media and politicians that China is the "state actor" behind the recent hacking of the networks of Australia's major political parties indicate how closely Canberra is trying to toe the line set by Washington, even at the cost of its relations with China", the editorial stated.
"I wouldn't jump to conclusions".