Yang has been detained for five years on charges of espionage that he and Australia have rejected.
The terms of the sentence mean Yang’s sentence could be commuted to life imprisonment for good behaviour.
“The Australian government is appalled by this outcome,” Australian Foreign Minister Penny Wong told reporters as she confirmed the sentence, the SBS News outlet reported.
Wong said Canberra would be responding “in the strongest terms” including by summoning the Chinese ambassador.
“I want to acknowledge the acute distress that Dr Yang and his family will be feeling today, coming after years of uncertainty,” she said.
Yang, a 58-year-old blogger and pro-democracy activist, was arrested in January 2019 when he arrived at Guangzhou airport with his wife, and was accused of having “endangered national security with particularly serious harm to the country and the people”.
Yang, a Chinese-born Australian, has denied the charges against him, as have his friends and family. A previous Australian government described the writer’s detention as “unacceptable”.
On Monday, supporters reacted with dismay to the sentence,
“He is punished by the Chinese government for his criticism of human rights abuses in China and his advocacy for universal values such as human rights, democracy and the rule of law,” friend and colleague Feng Chongyi was quoted as saying by the Sydney Morning Herald.
Feng said Yang’s family, who were in court, had told him of the sentence.
Feng previously told Al Jazeera that Yang worked for the Chinese Ministry of State Security (MSS) at the provincial level for 14 years and began writing spy novels as he became more frustrated with his work.
He moved to Australia in 2000 and five years later, began studying under Feng at the University of Technology Sydney, where he “transformed himself into a liberal”. At the time of his detention, he was working in New York.
Yang was put on trial in May 2021, having had limited access to lawyers. China has not revealed the exact charges against him or which country he is alleged to have been spying for.