"Chinese military intelligence services ultimately seek to acquire privileged military, political and economic intelligence that can provide China with a strategic and tactical advantage over the Five Eyes," the domestic security agencies from the Australia, the United States, Britain, Canada, and New Zealand said on Wednesday.
Although there have been similar warnings from individual countries in the past, the joint bulletin was described as unprecedented.
Beijing has repeatedly rejected such espionage claims, calling them "pure fabrication and malicious slander".
In the bulletin, the Five Eyes agencies said Chinese spies were particularly targeting those who specialised in defence, foreign affairs and intelligence, and military personnel, including those stationed in the Indo-Pacific region.
Also at risk were journalists, think tank employees or those with peripheral access to government data.
It said the spies used "an aggressive online recruitment strategy" with successful candidates then pressured to provide confidential information "for unspecified clients who are associated with the Chinese government".
Those who were recruited could be paid anywhere from a few hundred to several thousand dollars per report, and offered more for increasingly sensitive information, the bulletin said.
The US has previously warned about Chinese intelligence using deception to target current and former US government employees while Britain's MI5 security service in November cautioned lawmakers about Chinese agents trying to spy on parliament.
