Radioactive iodine 131 from the ruptured Japanese nuclear power plant has been found at slightly higher levels than normal in the air across some part of China.
Officials say the slight increase poses no danger to health, state-run CCTV reported.
"I can assure you that the nuclide iodine-131 recently found in some parts of China is only 0.001% higher than normal. This will not affect the environment and public health. So people do not need to take any protective measures and should work normally," said Wang Minzheng, Vice Director of National Nuclear Emergency Committee.
Sixteen nuclear accident emergency offices have been established in China since the Chernobyl nuclear disaster in the former Soviet Union in 1986.
All centres have been monitoring radiation levels since the nuclear accident in Japan.
China's government says it's ready to provide radiation protection, emergency monitoring and medical help to Japan, if required.