It means Chinese internet users lost 91.5 billion yuan, about 133 yuan on average by each internet using Chinese from July 1 last year to the first half of this year, the Internet Society of China said.
Nine per cent lost more than 1,000 yuan each, it said.
Each netizen spent an average of 3.6 hours dealing with spam and personal information theft, according to the society, whose membership covers China's major internet service providers and telecommunications operators.
Spam telephone calls irked the public the most, Hao Zhichao, deputy head of the malicious and spam message complaints center, which was set up by the society, was quoted as saying by the state-run Xinhua news agency.
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About 76 per cent of netizens received information on "prizes," which tried to direct them to fake websites masquerading as banks, internet firms and TV stations, and they also received fake information from the "police" or "social security," it said.
The society advised people to be careful when giving information to websites or institutions, avoid leaving too much individual information online and not to download unidentified software.
China had an online population of 688 million at the end of 2015, about half of the total population, according to the China Internet Network Information Centre.