China's Cyperspace Administration has closed nearly 1.8 million accounts on social networking and instant messaging services since it launched its anti-pornography campaign in April, state news agency Xinhua reported on Saturday.
The campaign has been focused on shutting down websites showing pornography and services used to solicit prostitution.
Most of the accounts closed were associated with microblogs, smart phone app WeChat and the instant messaging service QQ, Xinhua quoted the Cyberspace Administration as saying.
Many of the accounts were shut down by the companies owning the apps themselves after public complaints, Xinhua said. There was no immediate comment from any of the companies involved.
The Chinese government regularly launches anti-pornography campaigns because the ruling Communist Party considers it deeply offensive to public morale.
Mobile messaging apps are hugely popular in China. Tencent Holding Ltd's WeChat is among the biggest with more than 300 million users.