China's Internet servers were hit by at least 150 billion junk emails last year, becoming the world's second-largest destination for spam after the United States.
Junk emails accounted for nearly one-third of all emails in 2003, Xinhua news agency said, quoting the Internet Society of China.
"It's a great waste of resources," Gong Shaohui, a member of an anti-spam association, was quoted as saying. "Moreover, if China is dumped on with junk mail, less servers will be left in use here."
China already has the world's second-largest population of Web surfers after the United States. Email users often find messages selling get-rich schemes, Viagra and penile enlargements in their inboxes.
The government has said it plans to clean up email spam for fear some messages may have content deemed "subversive", such as pornography and anti-Communist opinions.
Internet experts around the world also criticize China for allowing too much spam to be sent to other countries.