The 64-year-old from Huzhou city was admitted to hospital on March 31 after being ill for two days, the official Xinhua news agency said, citing local authorities.
The man is the third person to be infected from the province of Zhejiang, where the disease has so far claimed one life. The other two deaths from the new strain of avian flu occurred in Shanghai.
The World Health Organization (WHO) on Wednesday ruled out the possibility of a pandemic because the disease is not thought to be transmitted from human to human.
In a separate development, a man in the central province of Hunan died from the H1N1 (swine) flu on Wednesday, reported Xinhua.
A 2009-2010 swine flu pandemic resulted in over 18,000 deaths, according to WHO estimates. But the strain, while highly contagious, is not thought to be more lethal than ordinary flu.