Mass occurs after the discovery of a dozen hospital-related cases treating coronavirus patients abroad.
In May, China tested the entire city of Wuhan, home to 11 million people and the epicentre of the global pandemic.
The country has largely controlled the virus.
This is in stark contrast to other parts of the world, where the number of cases and restrictions on variable gravity locking are still high.
In a post on Chinese social media site Weibo, the Qingdao Municipal Health Commission said that six new cases and six asymptomatic cases had been discovered.
They were all connected to the same hospital, the state Global Times said.
The Chinese government now has a massive testing strategy even when a new coronavirus group appears to be smaller, according to correspondents.
The National Health Commission said Monday that “the total city will be examined within five days. “
Some 114,862 more people, in addition to medical patients and newly hospitalized in hospitals in the city, had already tested negative, Qingdao Health Commission said.
Videos circulating online showed citizens queuing late on Sunday to verify, the Global Times reported, adding that some of the verification issues were open at 7 a. m. 11 p. m.
The new cases come a week after the Golden Week holiday in China, which has noticed millions of people across the country.
A Global Times report brought up by Qingdao’s Municipal Bureau of Culture and Tourism said the coastal city had gained 4. 47 million passengers in that period.
The near Jinan village in the same province as Qingdao has asked for a project on who has visited the town since 23 September, according to a report by The Paper.
Earlier this month, Qingdao announced that two port employees handling imported seafood had tested positive and were not known to have become more inflamed.
Daily coronavirus infections have decreased dramatically in China and, for the most part, the country appears to have recovered from the worst.
China has lately had 91,305 cases of viruses and the death toll is 4,746, according to WHO data.
China said another 11 million people in the city had been tested in the previous 10 days this year.
The BBC’s Reality Check estimated the figure to be close to nine million, but it is still a significant number of people.
Hundreds of verification centres have been opened, with thousands of workers involved.
They also mobilized groups to control others with disabilities, the elderly and others vulnerable in their homes.
A way to speed up the procedure for using batch or group tests.
In this process, a batch of five to 10 patterns was tested. Only if a pattern tested positive, the team would re-test individually to see who tested positive in the batch.