Chinese mobile phone users are being flooded with spam text messages, with 6.25 per cent of them receiving spam more than 40 times a week, according to a survey by the China Internet Society.

The survey, released on Tuesday, shows that 35 per cent of all 4,721 users randomly questioned across the country receive five to 10 spam messages a week, while 15 per cent get 10 to 20. On average, each user receives at least eight spam messages a week, questionnaires show.

Common junk messages include advertisements, swindles, information on illegal selling of vehicles, weapons or fake diplomas, and short message services (SMS) that users never signed up for.

Huang Chengqing, the society's secretary-general, said spam messages are usually sent from private individual mobile phones, through SMS providers such as websites, or from special equipment added to the mobile phone that enables the sender to send mass messages at a single time.

However, the survey shows that only 61 per cent of users have ever appealed to supervisory departments and about half of them do not know how to cancel unwanted SMS subscriptions.

"Such a limited number of complaints will not help change the existing situation," Huang said, adding that every user should be clear about how to protect their rights.

Lu Xiangdong, vice-president of China Mobile Communications Corporation, one of China's biggest mobile operators, said even he can't escape from spam messages.

In an anti-spam speech at a symposium on Tuesday in Beijing, Lu said he had just received an advertisement from an unknown number before he started the speech.

In order to control spam messages, mobile operators should be more vigilant about suspiciously large numbers of text messages from one sender, said Lu. On the other hand, mobile service providers should offer users more healthy content such as news, e-books and TV programmes.

To step up such efforts, China's four major mobile operators, China Mobile, China Unicom, China Telecom and China Netcom, joined 14 other service providers, including Sina.com and Sohu.com, to establish a "Green Mobile Culture" association on Tuesday. Members promised not to spread unhealthy or illegal information, and make further efforts to wipe out spam messages.

About 54 per cent of respondents to the China Internet Society's survey agree that mobile operators and service providers should play a bigger role in combating spam messages. About 64 per cent of people questioned also consider it necessary for the government to issue related laws to better regulate mobile services.

Figures from the Ministry of Information Industry show China had 449 million mobile phone users by last month, 56 million more than that of the end of last year.