Officials said that between the end of September and January they had investigated 436 cases, including about 130 at the request of overseas industry associations, and ordered 361 offenders to stop their infringements.
"Piracy of intellectual property on the Internet has seriously harmed the interests of copyright owners, leading to a large number of disputes--and thus disrupting the orderliness of the Internet," Yan Xiaohong, deputy director of the National Copyright Administration, told a news conference.
Yan said that in the latest action, authorities had imposed fines totaling 705,000 yuan ($91,000), confiscated 71 servers and transferred six cases to courts for prosecution. One of those had led to a conviction, he said.
Prominent cases included sites that offered downloads of software, textbooks, music and television shows. In one case, all the Internet cafes in Changchun, in the country's northeast, were found to be linked into a database of pirated films.
Chinese people habitually download pirated music and movies due to the high price of authorised copies and government restrictions on cultural imports; many Western movies are not even officially available.
Pirated music, movies and software are sold openly on Chinese streets, a major irritant in trade relations with the United States.
Official figures show China now has about 843,000 Web sites and 140 million Internet users, making it the world's second largest Internet market.
Yan declined to estimate how many of those sites contained pirated material, but called for understanding from China's trade partners that it was working in earnest to address the issue.
"With the Internet developing so quickly, I'm afraid that in China, as elsewhere, it's going to take some time before we can effectively manage it," he said.