The rally, announced online as an "innocent stroll," turned into a face-off between helmeted police officers and protesters chanting slogans and carrying banners reading "Anti-nuclear" and "We want children, not atoms,' China's official Xinhua News Agency reported.
The public had been given 10 days to comment on the project after a risk evaluation report on the $6 billion facility was released July 4. Protesters said that wasn't enough time to fully deliberate the plant's possible dangers.
The local government announced the cancellation of the project in a one-line statement saying it "has decided to respect the public opinion and will not consider CNNC's Longwan industrial park project."
Some protesters expressed concern the project may have only been postponed.
The uranium processing plant, about 60 miles from Hong Kong, would have been capable of supplying half the fuel for the country's atomic energy needs.
Cancellation of the plant deals a blow to China's plans to get more of its energy from nuclear power as it works to move away from more air polluting sources such as coal, The New York Times reported.
By 2020, the government wants nuclear power to supply at least 5 percent of the country's power, up from 2 percent currently.